xref: /openbmc/linux/drivers/spi/spi-sh-msiof.c (revision 77d84ff8)
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 = 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)
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 	sh_msiof_write(p, TMDR1, 0xe2000005 | (lsb_first << 24));
186 	sh_msiof_write(p, RMDR1, 0x22000005 | (lsb_first << 24));
187 
188 	tmp = 0xa0000000;
189 	tmp |= cpol << 30; /* TSCKIZ */
190 	tmp |= cpol << 28; /* RSCKIZ */
191 
192 	edge = cpol ^ !cpha;
193 
194 	tmp |= edge << 27; /* TEDG */
195 	tmp |= edge << 26; /* REDG */
196 	tmp |= (tx_hi_z ? 2 : 0) << 22; /* TXDIZ */
197 	sh_msiof_write(p, CTR, tmp);
198 }
199 
200 static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
201 				       const void *tx_buf, void *rx_buf,
202 				       u32 bits, u32 words)
203 {
204 	u32 dr2 = ((bits - 1) << 24) | ((words - 1) << 16);
205 
206 	if (tx_buf)
207 		sh_msiof_write(p, TMDR2, dr2);
208 	else
209 		sh_msiof_write(p, TMDR2, dr2 | 1);
210 
211 	if (rx_buf)
212 		sh_msiof_write(p, RMDR2, dr2);
213 
214 	sh_msiof_write(p, IER, STR_TEOF | STR_REOF);
215 }
216 
217 static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
218 {
219 	sh_msiof_write(p, STR, sh_msiof_read(p, STR));
220 }
221 
222 static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
223 				      const void *tx_buf, int words, int fs)
224 {
225 	const u8 *buf_8 = tx_buf;
226 	int k;
227 
228 	for (k = 0; k < words; k++)
229 		sh_msiof_write(p, TFDR, buf_8[k] << fs);
230 }
231 
232 static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
233 				       const void *tx_buf, int words, int fs)
234 {
235 	const u16 *buf_16 = tx_buf;
236 	int k;
237 
238 	for (k = 0; k < words; k++)
239 		sh_msiof_write(p, TFDR, buf_16[k] << fs);
240 }
241 
242 static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
243 					const void *tx_buf, int words, int fs)
244 {
245 	const u16 *buf_16 = tx_buf;
246 	int k;
247 
248 	for (k = 0; k < words; k++)
249 		sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
250 }
251 
252 static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
253 				       const void *tx_buf, int words, int fs)
254 {
255 	const u32 *buf_32 = tx_buf;
256 	int k;
257 
258 	for (k = 0; k < words; k++)
259 		sh_msiof_write(p, TFDR, buf_32[k] << fs);
260 }
261 
262 static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
263 					const void *tx_buf, int words, int fs)
264 {
265 	const u32 *buf_32 = tx_buf;
266 	int k;
267 
268 	for (k = 0; k < words; k++)
269 		sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
270 }
271 
272 static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
273 					const void *tx_buf, int words, int fs)
274 {
275 	const u32 *buf_32 = tx_buf;
276 	int k;
277 
278 	for (k = 0; k < words; k++)
279 		sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
280 }
281 
282 static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
283 					 const void *tx_buf, int words, int fs)
284 {
285 	const u32 *buf_32 = tx_buf;
286 	int k;
287 
288 	for (k = 0; k < words; k++)
289 		sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
290 }
291 
292 static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
293 				     void *rx_buf, int words, int fs)
294 {
295 	u8 *buf_8 = rx_buf;
296 	int k;
297 
298 	for (k = 0; k < words; k++)
299 		buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
300 }
301 
302 static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
303 				      void *rx_buf, int words, int fs)
304 {
305 	u16 *buf_16 = rx_buf;
306 	int k;
307 
308 	for (k = 0; k < words; k++)
309 		buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
310 }
311 
312 static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
313 				       void *rx_buf, int words, int fs)
314 {
315 	u16 *buf_16 = rx_buf;
316 	int k;
317 
318 	for (k = 0; k < words; k++)
319 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
320 }
321 
322 static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
323 				      void *rx_buf, int words, int fs)
324 {
325 	u32 *buf_32 = rx_buf;
326 	int k;
327 
328 	for (k = 0; k < words; k++)
329 		buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
330 }
331 
332 static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
333 				       void *rx_buf, int words, int fs)
334 {
335 	u32 *buf_32 = rx_buf;
336 	int k;
337 
338 	for (k = 0; k < words; k++)
339 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
340 }
341 
342 static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
343 				       void *rx_buf, int words, int fs)
344 {
345 	u32 *buf_32 = rx_buf;
346 	int k;
347 
348 	for (k = 0; k < words; k++)
349 		buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
350 }
351 
352 static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
353 				       void *rx_buf, int words, int fs)
354 {
355 	u32 *buf_32 = rx_buf;
356 	int k;
357 
358 	for (k = 0; k < words; k++)
359 		put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
360 }
361 
362 static int sh_msiof_spi_bits(struct spi_device *spi, struct spi_transfer *t)
363 {
364 	int bits;
365 
366 	bits = t ? t->bits_per_word : 0;
367 	if (!bits)
368 		bits = spi->bits_per_word;
369 	return bits;
370 }
371 
372 static unsigned long sh_msiof_spi_hz(struct spi_device *spi,
373 				     struct spi_transfer *t)
374 {
375 	unsigned long hz;
376 
377 	hz = t ? t->speed_hz : 0;
378 	if (!hz)
379 		hz = spi->max_speed_hz;
380 	return hz;
381 }
382 
383 static int sh_msiof_spi_setup_transfer(struct spi_device *spi,
384 				       struct spi_transfer *t)
385 {
386 	int bits;
387 
388 	/* noting to check hz values against since parent clock is disabled */
389 
390 	bits = sh_msiof_spi_bits(spi, t);
391 	if (bits < 8)
392 		return -EINVAL;
393 	if (bits > 32)
394 		return -EINVAL;
395 
396 	return spi_bitbang_setup_transfer(spi, t);
397 }
398 
399 static void sh_msiof_spi_chipselect(struct spi_device *spi, int is_on)
400 {
401 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
402 	int value;
403 
404 	/* chip select is active low unless SPI_CS_HIGH is set */
405 	if (spi->mode & SPI_CS_HIGH)
406 		value = (is_on == BITBANG_CS_ACTIVE) ? 1 : 0;
407 	else
408 		value = (is_on == BITBANG_CS_ACTIVE) ? 0 : 1;
409 
410 	if (is_on == BITBANG_CS_ACTIVE) {
411 		if (!test_and_set_bit(0, &p->flags)) {
412 			pm_runtime_get_sync(&p->pdev->dev);
413 			clk_enable(p->clk);
414 		}
415 
416 		/* Configure pins before asserting CS */
417 		sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
418 					  !!(spi->mode & SPI_CPHA),
419 					  !!(spi->mode & SPI_3WIRE),
420 					  !!(spi->mode & SPI_LSB_FIRST));
421 	}
422 
423 	/* use spi->controller data for CS (same strategy as spi_gpio) */
424 	gpio_set_value((unsigned)spi->controller_data, value);
425 
426 	if (is_on == BITBANG_CS_INACTIVE) {
427 		if (test_and_clear_bit(0, &p->flags)) {
428 			clk_disable(p->clk);
429 			pm_runtime_put(&p->pdev->dev);
430 		}
431 	}
432 }
433 
434 static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
435 				  void (*tx_fifo)(struct sh_msiof_spi_priv *,
436 						  const void *, int, int),
437 				  void (*rx_fifo)(struct sh_msiof_spi_priv *,
438 						  void *, int, int),
439 				  const void *tx_buf, void *rx_buf,
440 				  int words, int bits)
441 {
442 	int fifo_shift;
443 	int ret;
444 
445 	/* limit maximum word transfer to rx/tx fifo size */
446 	if (tx_buf)
447 		words = min_t(int, words, p->tx_fifo_size);
448 	if (rx_buf)
449 		words = min_t(int, words, p->rx_fifo_size);
450 
451 	/* the fifo contents need shifting */
452 	fifo_shift = 32 - bits;
453 
454 	/* setup msiof transfer mode registers */
455 	sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);
456 
457 	/* write tx fifo */
458 	if (tx_buf)
459 		tx_fifo(p, tx_buf, words, fifo_shift);
460 
461 	/* setup clock and rx/tx signals */
462 	ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
463 	if (rx_buf)
464 		ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
465 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);
466 
467 	/* start by setting frame bit */
468 	reinit_completion(&p->done);
469 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
470 	if (ret) {
471 		dev_err(&p->pdev->dev, "failed to start hardware\n");
472 		goto err;
473 	}
474 
475 	/* wait for tx fifo to be emptied / rx fifo to be filled */
476 	wait_for_completion(&p->done);
477 
478 	/* read rx fifo */
479 	if (rx_buf)
480 		rx_fifo(p, rx_buf, words, fifo_shift);
481 
482 	/* clear status bits */
483 	sh_msiof_reset_str(p);
484 
485 	/* shut down frame, tx/tx and clock signals */
486 	ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
487 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
488 	if (rx_buf)
489 		ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
490 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
491 	if (ret) {
492 		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
493 		goto err;
494 	}
495 
496 	return words;
497 
498  err:
499 	sh_msiof_write(p, IER, 0);
500 	return ret;
501 }
502 
503 static int sh_msiof_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
504 {
505 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
506 	void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
507 	void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
508 	int bits;
509 	int bytes_per_word;
510 	int bytes_done;
511 	int words;
512 	int n;
513 	bool swab;
514 
515 	bits = sh_msiof_spi_bits(spi, t);
516 
517 	if (bits <= 8 && t->len > 15 && !(t->len & 3)) {
518 		bits = 32;
519 		swab = true;
520 	} else {
521 		swab = false;
522 	}
523 
524 	/* setup bytes per word and fifo read/write functions */
525 	if (bits <= 8) {
526 		bytes_per_word = 1;
527 		tx_fifo = sh_msiof_spi_write_fifo_8;
528 		rx_fifo = sh_msiof_spi_read_fifo_8;
529 	} else if (bits <= 16) {
530 		bytes_per_word = 2;
531 		if ((unsigned long)t->tx_buf & 0x01)
532 			tx_fifo = sh_msiof_spi_write_fifo_16u;
533 		else
534 			tx_fifo = sh_msiof_spi_write_fifo_16;
535 
536 		if ((unsigned long)t->rx_buf & 0x01)
537 			rx_fifo = sh_msiof_spi_read_fifo_16u;
538 		else
539 			rx_fifo = sh_msiof_spi_read_fifo_16;
540 	} else if (swab) {
541 		bytes_per_word = 4;
542 		if ((unsigned long)t->tx_buf & 0x03)
543 			tx_fifo = sh_msiof_spi_write_fifo_s32u;
544 		else
545 			tx_fifo = sh_msiof_spi_write_fifo_s32;
546 
547 		if ((unsigned long)t->rx_buf & 0x03)
548 			rx_fifo = sh_msiof_spi_read_fifo_s32u;
549 		else
550 			rx_fifo = sh_msiof_spi_read_fifo_s32;
551 	} else {
552 		bytes_per_word = 4;
553 		if ((unsigned long)t->tx_buf & 0x03)
554 			tx_fifo = sh_msiof_spi_write_fifo_32u;
555 		else
556 			tx_fifo = sh_msiof_spi_write_fifo_32;
557 
558 		if ((unsigned long)t->rx_buf & 0x03)
559 			rx_fifo = sh_msiof_spi_read_fifo_32u;
560 		else
561 			rx_fifo = sh_msiof_spi_read_fifo_32;
562 	}
563 
564 	/* setup clocks (clock already enabled in chipselect()) */
565 	sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk),
566 				  sh_msiof_spi_hz(spi, t));
567 
568 	/* transfer in fifo sized chunks */
569 	words = t->len / bytes_per_word;
570 	bytes_done = 0;
571 
572 	while (bytes_done < t->len) {
573 		void *rx_buf = t->rx_buf ? t->rx_buf + bytes_done : NULL;
574 		const void *tx_buf = t->tx_buf ? t->tx_buf + bytes_done : NULL;
575 		n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo,
576 					   tx_buf,
577 					   rx_buf,
578 					   words, bits);
579 		if (n < 0)
580 			break;
581 
582 		bytes_done += n * bytes_per_word;
583 		words -= n;
584 	}
585 
586 	return bytes_done;
587 }
588 
589 static u32 sh_msiof_spi_txrx_word(struct spi_device *spi, unsigned nsecs,
590 				  u32 word, u8 bits)
591 {
592 	BUG(); /* unused but needed by bitbang code */
593 	return 0;
594 }
595 
596 #ifdef CONFIG_OF
597 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
598 {
599 	struct sh_msiof_spi_info *info;
600 	struct device_node *np = dev->of_node;
601 	u32 num_cs = 0;
602 
603 	info = devm_kzalloc(dev, sizeof(struct sh_msiof_spi_info), GFP_KERNEL);
604 	if (!info) {
605 		dev_err(dev, "failed to allocate setup data\n");
606 		return NULL;
607 	}
608 
609 	/* Parse the MSIOF properties */
610 	of_property_read_u32(np, "num-cs", &num_cs);
611 	of_property_read_u32(np, "renesas,tx-fifo-size",
612 					&info->tx_fifo_override);
613 	of_property_read_u32(np, "renesas,rx-fifo-size",
614 					&info->rx_fifo_override);
615 
616 	info->num_chipselect = num_cs;
617 
618 	return info;
619 }
620 #else
621 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
622 {
623 	return NULL;
624 }
625 #endif
626 
627 static int sh_msiof_spi_probe(struct platform_device *pdev)
628 {
629 	struct resource	*r;
630 	struct spi_master *master;
631 	struct sh_msiof_spi_priv *p;
632 	int i;
633 	int ret;
634 
635 	master = spi_alloc_master(&pdev->dev, sizeof(struct sh_msiof_spi_priv));
636 	if (master == NULL) {
637 		dev_err(&pdev->dev, "failed to allocate spi master\n");
638 		ret = -ENOMEM;
639 		goto err0;
640 	}
641 
642 	p = spi_master_get_devdata(master);
643 
644 	platform_set_drvdata(pdev, p);
645 	if (pdev->dev.of_node)
646 		p->info = sh_msiof_spi_parse_dt(&pdev->dev);
647 	else
648 		p->info = dev_get_platdata(&pdev->dev);
649 
650 	if (!p->info) {
651 		dev_err(&pdev->dev, "failed to obtain device info\n");
652 		ret = -ENXIO;
653 		goto err1;
654 	}
655 
656 	init_completion(&p->done);
657 
658 	p->clk = clk_get(&pdev->dev, NULL);
659 	if (IS_ERR(p->clk)) {
660 		dev_err(&pdev->dev, "cannot get clock\n");
661 		ret = PTR_ERR(p->clk);
662 		goto err1;
663 	}
664 
665 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
666 	i = platform_get_irq(pdev, 0);
667 	if (!r || i < 0) {
668 		dev_err(&pdev->dev, "cannot get platform resources\n");
669 		ret = -ENOENT;
670 		goto err2;
671 	}
672 	p->mapbase = ioremap_nocache(r->start, resource_size(r));
673 	if (!p->mapbase) {
674 		dev_err(&pdev->dev, "unable to ioremap\n");
675 		ret = -ENXIO;
676 		goto err2;
677 	}
678 
679 	ret = request_irq(i, sh_msiof_spi_irq, 0,
680 			  dev_name(&pdev->dev), p);
681 	if (ret) {
682 		dev_err(&pdev->dev, "unable to request irq\n");
683 		goto err3;
684 	}
685 
686 	p->pdev = pdev;
687 	pm_runtime_enable(&pdev->dev);
688 
689 	/* The standard version of MSIOF use 64 word FIFOs */
690 	p->tx_fifo_size = 64;
691 	p->rx_fifo_size = 64;
692 
693 	/* Platform data may override FIFO sizes */
694 	if (p->info->tx_fifo_override)
695 		p->tx_fifo_size = p->info->tx_fifo_override;
696 	if (p->info->rx_fifo_override)
697 		p->rx_fifo_size = p->info->rx_fifo_override;
698 
699 	/* init master and bitbang code */
700 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
701 	master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
702 	master->flags = 0;
703 	master->bus_num = pdev->id;
704 	master->num_chipselect = p->info->num_chipselect;
705 	master->setup = spi_bitbang_setup;
706 	master->cleanup = spi_bitbang_cleanup;
707 
708 	p->bitbang.master = master;
709 	p->bitbang.chipselect = sh_msiof_spi_chipselect;
710 	p->bitbang.setup_transfer = sh_msiof_spi_setup_transfer;
711 	p->bitbang.txrx_bufs = sh_msiof_spi_txrx;
712 	p->bitbang.txrx_word[SPI_MODE_0] = sh_msiof_spi_txrx_word;
713 	p->bitbang.txrx_word[SPI_MODE_1] = sh_msiof_spi_txrx_word;
714 	p->bitbang.txrx_word[SPI_MODE_2] = sh_msiof_spi_txrx_word;
715 	p->bitbang.txrx_word[SPI_MODE_3] = sh_msiof_spi_txrx_word;
716 
717 	ret = spi_bitbang_start(&p->bitbang);
718 	if (ret == 0)
719 		return 0;
720 
721 	pm_runtime_disable(&pdev->dev);
722  err3:
723 	iounmap(p->mapbase);
724  err2:
725 	clk_put(p->clk);
726  err1:
727 	spi_master_put(master);
728  err0:
729 	return ret;
730 }
731 
732 static int sh_msiof_spi_remove(struct platform_device *pdev)
733 {
734 	struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
735 	int ret;
736 
737 	ret = spi_bitbang_stop(&p->bitbang);
738 	if (!ret) {
739 		pm_runtime_disable(&pdev->dev);
740 		free_irq(platform_get_irq(pdev, 0), p);
741 		iounmap(p->mapbase);
742 		clk_put(p->clk);
743 		spi_master_put(p->bitbang.master);
744 	}
745 	return ret;
746 }
747 
748 #ifdef CONFIG_OF
749 static const struct of_device_id sh_msiof_match[] = {
750 	{ .compatible = "renesas,sh-msiof", },
751 	{ .compatible = "renesas,sh-mobile-msiof", },
752 	{},
753 };
754 MODULE_DEVICE_TABLE(of, sh_msiof_match);
755 #endif
756 
757 static struct platform_driver sh_msiof_spi_drv = {
758 	.probe		= sh_msiof_spi_probe,
759 	.remove		= sh_msiof_spi_remove,
760 	.driver		= {
761 		.name		= "spi_sh_msiof",
762 		.owner		= THIS_MODULE,
763 		.of_match_table = of_match_ptr(sh_msiof_match),
764 	},
765 };
766 module_platform_driver(sh_msiof_spi_drv);
767 
768 MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
769 MODULE_AUTHOR("Magnus Damm");
770 MODULE_LICENSE("GPL v2");
771 MODULE_ALIAS("platform:spi_sh_msiof");
772