xref: /openbmc/linux/drivers/spi/spi-sh-msiof.c (revision afb46f79)
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/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/of.h>
23 #include <linux/of_device.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 
30 #include <asm/unaligned.h>
31 
32 
33 struct sh_msiof_chipdata {
34 	u16 tx_fifo_size;
35 	u16 rx_fifo_size;
36 	u16 master_flags;
37 };
38 
39 struct sh_msiof_spi_priv {
40 	void __iomem *mapbase;
41 	struct clk *clk;
42 	struct platform_device *pdev;
43 	const struct sh_msiof_chipdata *chipdata;
44 	struct sh_msiof_spi_info *info;
45 	struct completion done;
46 	int tx_fifo_size;
47 	int rx_fifo_size;
48 };
49 
50 #define TMDR1	0x00	/* Transmit Mode Register 1 */
51 #define TMDR2	0x04	/* Transmit Mode Register 2 */
52 #define TMDR3	0x08	/* Transmit Mode Register 3 */
53 #define RMDR1	0x10	/* Receive Mode Register 1 */
54 #define RMDR2	0x14	/* Receive Mode Register 2 */
55 #define RMDR3	0x18	/* Receive Mode Register 3 */
56 #define TSCR	0x20	/* Transmit Clock Select Register */
57 #define RSCR	0x22	/* Receive Clock Select Register (SH, A1, APE6) */
58 #define CTR	0x28	/* Control Register */
59 #define FCTR	0x30	/* FIFO Control Register */
60 #define STR	0x40	/* Status Register */
61 #define IER	0x44	/* Interrupt Enable Register */
62 #define TDR1	0x48	/* Transmit Control Data Register 1 (SH, A1) */
63 #define TDR2	0x4c	/* Transmit Control Data Register 2 (SH, A1) */
64 #define TFDR	0x50	/* Transmit FIFO Data Register */
65 #define RDR1	0x58	/* Receive Control Data Register 1 (SH, A1) */
66 #define RDR2	0x5c	/* Receive Control Data Register 2 (SH, A1) */
67 #define RFDR	0x60	/* Receive FIFO Data Register */
68 
69 /* TMDR1 and RMDR1 */
70 #define MDR1_TRMD	 0x80000000 /* Transfer Mode (1 = Master mode) */
71 #define MDR1_SYNCMD_MASK 0x30000000 /* SYNC Mode */
72 #define MDR1_SYNCMD_SPI	 0x20000000 /*   Level mode/SPI */
73 #define MDR1_SYNCMD_LR	 0x30000000 /*   L/R mode */
74 #define MDR1_SYNCAC_SHIFT	 25 /* Sync Polarity (1 = Active-low) */
75 #define MDR1_BITLSB_SHIFT	 24 /* MSB/LSB First (1 = LSB first) */
76 #define MDR1_FLD_MASK	 0x000000c0 /* Frame Sync Signal Interval (0-3) */
77 #define MDR1_FLD_SHIFT		  2
78 #define MDR1_XXSTP	 0x00000001 /* Transmission/Reception Stop on FIFO */
79 /* TMDR1 */
80 #define TMDR1_PCON	 0x40000000 /* Transfer Signal Connection */
81 
82 /* TMDR2 and RMDR2 */
83 #define MDR2_BITLEN1(i)	(((i) - 1) << 24) /* Data Size (8-32 bits) */
84 #define MDR2_WDLEN1(i)	(((i) - 1) << 16) /* Word Count (1-64/256 (SH, A1))) */
85 #define MDR2_GRPMASK1	0x00000001 /* Group Output Mask 1 (SH, A1) */
86 
87 /* TSCR and RSCR */
88 #define SCR_BRPS_MASK	    0x1f00 /* Prescaler Setting (1-32) */
89 #define SCR_BRPS(i)	(((i) - 1) << 8)
90 #define SCR_BRDV_MASK	    0x0007 /* Baud Rate Generator's Division Ratio */
91 #define SCR_BRDV_DIV_2	    0x0000
92 #define SCR_BRDV_DIV_4	    0x0001
93 #define SCR_BRDV_DIV_8	    0x0002
94 #define SCR_BRDV_DIV_16	    0x0003
95 #define SCR_BRDV_DIV_32	    0x0004
96 #define SCR_BRDV_DIV_1	    0x0007
97 
98 /* CTR */
99 #define CTR_TSCKIZ_MASK	0xc0000000 /* Transmit Clock I/O Polarity Select */
100 #define CTR_TSCKIZ_SCK	0x80000000 /*   Disable SCK when TX disabled */
101 #define CTR_TSCKIZ_POL_SHIFT	30 /*   Transmit Clock Polarity */
102 #define CTR_RSCKIZ_MASK	0x30000000 /* Receive Clock Polarity Select */
103 #define CTR_RSCKIZ_SCK	0x20000000 /*   Must match CTR_TSCKIZ_SCK */
104 #define CTR_RSCKIZ_POL_SHIFT	28 /*   Receive Clock Polarity */
105 #define CTR_TEDG_SHIFT		27 /* Transmit Timing (1 = falling edge) */
106 #define CTR_REDG_SHIFT		26 /* Receive Timing (1 = falling edge) */
107 #define CTR_TXDIZ_MASK	0x00c00000 /* Pin Output When TX is Disabled */
108 #define CTR_TXDIZ_LOW	0x00000000 /*   0 */
109 #define CTR_TXDIZ_HIGH	0x00400000 /*   1 */
110 #define CTR_TXDIZ_HIZ	0x00800000 /*   High-impedance */
111 #define CTR_TSCKE	0x00008000 /* Transmit Serial Clock Output Enable */
112 #define CTR_TFSE	0x00004000 /* Transmit Frame Sync Signal Output Enable */
113 #define CTR_TXE		0x00000200 /* Transmit Enable */
114 #define CTR_RXE		0x00000100 /* Receive Enable */
115 
116 /* STR and IER */
117 #define STR_TEOF	0x00800000 /* Frame Transmission End */
118 #define STR_REOF	0x00000080 /* Frame Reception End */
119 
120 
121 static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs)
122 {
123 	switch (reg_offs) {
124 	case TSCR:
125 	case RSCR:
126 		return ioread16(p->mapbase + reg_offs);
127 	default:
128 		return ioread32(p->mapbase + reg_offs);
129 	}
130 }
131 
132 static void sh_msiof_write(struct sh_msiof_spi_priv *p, int reg_offs,
133 			   u32 value)
134 {
135 	switch (reg_offs) {
136 	case TSCR:
137 	case RSCR:
138 		iowrite16(value, p->mapbase + reg_offs);
139 		break;
140 	default:
141 		iowrite32(value, p->mapbase + reg_offs);
142 		break;
143 	}
144 }
145 
146 static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv *p,
147 				    u32 clr, u32 set)
148 {
149 	u32 mask = clr | set;
150 	u32 data;
151 	int k;
152 
153 	data = sh_msiof_read(p, CTR);
154 	data &= ~clr;
155 	data |= set;
156 	sh_msiof_write(p, CTR, data);
157 
158 	for (k = 100; k > 0; k--) {
159 		if ((sh_msiof_read(p, CTR) & mask) == set)
160 			break;
161 
162 		udelay(10);
163 	}
164 
165 	return k > 0 ? 0 : -ETIMEDOUT;
166 }
167 
168 static irqreturn_t sh_msiof_spi_irq(int irq, void *data)
169 {
170 	struct sh_msiof_spi_priv *p = data;
171 
172 	/* just disable the interrupt and wake up */
173 	sh_msiof_write(p, IER, 0);
174 	complete(&p->done);
175 
176 	return IRQ_HANDLED;
177 }
178 
179 static struct {
180 	unsigned short div;
181 	unsigned short scr;
182 } const sh_msiof_spi_clk_table[] = {
183 	{ 1,	SCR_BRPS( 1) | SCR_BRDV_DIV_1 },
184 	{ 2,	SCR_BRPS( 1) | SCR_BRDV_DIV_2 },
185 	{ 4,	SCR_BRPS( 1) | SCR_BRDV_DIV_4 },
186 	{ 8,	SCR_BRPS( 1) | SCR_BRDV_DIV_8 },
187 	{ 16,	SCR_BRPS( 1) | SCR_BRDV_DIV_16 },
188 	{ 32,	SCR_BRPS( 1) | SCR_BRDV_DIV_32 },
189 	{ 64,	SCR_BRPS(32) | SCR_BRDV_DIV_2 },
190 	{ 128,	SCR_BRPS(32) | SCR_BRDV_DIV_4 },
191 	{ 256,	SCR_BRPS(32) | SCR_BRDV_DIV_8 },
192 	{ 512,	SCR_BRPS(32) | SCR_BRDV_DIV_16 },
193 	{ 1024,	SCR_BRPS(32) | SCR_BRDV_DIV_32 },
194 };
195 
196 static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
197 				      unsigned long parent_rate, u32 spi_hz)
198 {
199 	unsigned long div = 1024;
200 	size_t k;
201 
202 	if (!WARN_ON(!spi_hz || !parent_rate))
203 		div = DIV_ROUND_UP(parent_rate, spi_hz);
204 
205 	/* TODO: make more fine grained */
206 
207 	for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_clk_table); k++) {
208 		if (sh_msiof_spi_clk_table[k].div >= div)
209 			break;
210 	}
211 
212 	k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_clk_table) - 1);
213 
214 	sh_msiof_write(p, TSCR, sh_msiof_spi_clk_table[k].scr);
215 	if (!(p->chipdata->master_flags & SPI_MASTER_MUST_TX))
216 		sh_msiof_write(p, RSCR, sh_msiof_spi_clk_table[k].scr);
217 }
218 
219 static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
220 				      u32 cpol, u32 cpha,
221 				      u32 tx_hi_z, u32 lsb_first, u32 cs_high)
222 {
223 	u32 tmp;
224 	int edge;
225 
226 	/*
227 	 * CPOL CPHA     TSCKIZ RSCKIZ TEDG REDG
228 	 *    0    0         10     10    1    1
229 	 *    0    1         10     10    0    0
230 	 *    1    0         11     11    0    0
231 	 *    1    1         11     11    1    1
232 	 */
233 	sh_msiof_write(p, FCTR, 0);
234 
235 	tmp = MDR1_SYNCMD_SPI | 1 << MDR1_FLD_SHIFT | MDR1_XXSTP;
236 	tmp |= !cs_high << MDR1_SYNCAC_SHIFT;
237 	tmp |= lsb_first << MDR1_BITLSB_SHIFT;
238 	sh_msiof_write(p, TMDR1, tmp | MDR1_TRMD | TMDR1_PCON);
239 	if (p->chipdata->master_flags & SPI_MASTER_MUST_TX) {
240 		/* These bits are reserved if RX needs TX */
241 		tmp &= ~0x0000ffff;
242 	}
243 	sh_msiof_write(p, RMDR1, tmp);
244 
245 	tmp = 0;
246 	tmp |= CTR_TSCKIZ_SCK | cpol << CTR_TSCKIZ_POL_SHIFT;
247 	tmp |= CTR_RSCKIZ_SCK | cpol << CTR_RSCKIZ_POL_SHIFT;
248 
249 	edge = cpol ^ !cpha;
250 
251 	tmp |= edge << CTR_TEDG_SHIFT;
252 	tmp |= edge << CTR_REDG_SHIFT;
253 	tmp |= tx_hi_z ? CTR_TXDIZ_HIZ : CTR_TXDIZ_LOW;
254 	sh_msiof_write(p, CTR, tmp);
255 }
256 
257 static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
258 				       const void *tx_buf, void *rx_buf,
259 				       u32 bits, u32 words)
260 {
261 	u32 dr2 = MDR2_BITLEN1(bits) | MDR2_WDLEN1(words);
262 
263 	if (tx_buf || (p->chipdata->master_flags & SPI_MASTER_MUST_TX))
264 		sh_msiof_write(p, TMDR2, dr2);
265 	else
266 		sh_msiof_write(p, TMDR2, dr2 | MDR2_GRPMASK1);
267 
268 	if (rx_buf)
269 		sh_msiof_write(p, RMDR2, dr2);
270 
271 	sh_msiof_write(p, IER, STR_TEOF | STR_REOF);
272 }
273 
274 static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
275 {
276 	sh_msiof_write(p, STR, sh_msiof_read(p, STR));
277 }
278 
279 static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
280 				      const void *tx_buf, int words, int fs)
281 {
282 	const u8 *buf_8 = tx_buf;
283 	int k;
284 
285 	for (k = 0; k < words; k++)
286 		sh_msiof_write(p, TFDR, buf_8[k] << fs);
287 }
288 
289 static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
290 				       const void *tx_buf, int words, int fs)
291 {
292 	const u16 *buf_16 = tx_buf;
293 	int k;
294 
295 	for (k = 0; k < words; k++)
296 		sh_msiof_write(p, TFDR, buf_16[k] << fs);
297 }
298 
299 static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
300 					const void *tx_buf, int words, int fs)
301 {
302 	const u16 *buf_16 = tx_buf;
303 	int k;
304 
305 	for (k = 0; k < words; k++)
306 		sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
307 }
308 
309 static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
310 				       const void *tx_buf, int words, int fs)
311 {
312 	const u32 *buf_32 = tx_buf;
313 	int k;
314 
315 	for (k = 0; k < words; k++)
316 		sh_msiof_write(p, TFDR, buf_32[k] << fs);
317 }
318 
319 static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
320 					const void *tx_buf, int words, int fs)
321 {
322 	const u32 *buf_32 = tx_buf;
323 	int k;
324 
325 	for (k = 0; k < words; k++)
326 		sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
327 }
328 
329 static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
330 					const void *tx_buf, int words, int fs)
331 {
332 	const u32 *buf_32 = tx_buf;
333 	int k;
334 
335 	for (k = 0; k < words; k++)
336 		sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
337 }
338 
339 static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
340 					 const void *tx_buf, int words, int fs)
341 {
342 	const u32 *buf_32 = tx_buf;
343 	int k;
344 
345 	for (k = 0; k < words; k++)
346 		sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
347 }
348 
349 static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
350 				     void *rx_buf, int words, int fs)
351 {
352 	u8 *buf_8 = rx_buf;
353 	int k;
354 
355 	for (k = 0; k < words; k++)
356 		buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
357 }
358 
359 static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
360 				      void *rx_buf, int words, int fs)
361 {
362 	u16 *buf_16 = rx_buf;
363 	int k;
364 
365 	for (k = 0; k < words; k++)
366 		buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
367 }
368 
369 static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
370 				       void *rx_buf, int words, int fs)
371 {
372 	u16 *buf_16 = rx_buf;
373 	int k;
374 
375 	for (k = 0; k < words; k++)
376 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
377 }
378 
379 static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
380 				      void *rx_buf, int words, int fs)
381 {
382 	u32 *buf_32 = rx_buf;
383 	int k;
384 
385 	for (k = 0; k < words; k++)
386 		buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
387 }
388 
389 static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
390 				       void *rx_buf, int words, int fs)
391 {
392 	u32 *buf_32 = rx_buf;
393 	int k;
394 
395 	for (k = 0; k < words; k++)
396 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
397 }
398 
399 static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
400 				       void *rx_buf, int words, int fs)
401 {
402 	u32 *buf_32 = rx_buf;
403 	int k;
404 
405 	for (k = 0; k < words; k++)
406 		buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
407 }
408 
409 static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
410 				       void *rx_buf, int words, int fs)
411 {
412 	u32 *buf_32 = rx_buf;
413 	int k;
414 
415 	for (k = 0; k < words; k++)
416 		put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
417 }
418 
419 static int sh_msiof_spi_setup(struct spi_device *spi)
420 {
421 	struct device_node	*np = spi->master->dev.of_node;
422 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
423 
424 	if (!np) {
425 		/*
426 		 * Use spi->controller_data for CS (same strategy as spi_gpio),
427 		 * if any. otherwise let HW control CS
428 		 */
429 		spi->cs_gpio = (uintptr_t)spi->controller_data;
430 	}
431 
432 	/* Configure pins before deasserting CS */
433 	sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
434 				  !!(spi->mode & SPI_CPHA),
435 				  !!(spi->mode & SPI_3WIRE),
436 				  !!(spi->mode & SPI_LSB_FIRST),
437 				  !!(spi->mode & SPI_CS_HIGH));
438 
439 	if (spi->cs_gpio >= 0)
440 		gpio_set_value(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
441 
442 	return 0;
443 }
444 
445 static int sh_msiof_prepare_message(struct spi_master *master,
446 				    struct spi_message *msg)
447 {
448 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
449 	const struct spi_device *spi = msg->spi;
450 
451 	/* Configure pins before asserting CS */
452 	sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
453 				  !!(spi->mode & SPI_CPHA),
454 				  !!(spi->mode & SPI_3WIRE),
455 				  !!(spi->mode & SPI_LSB_FIRST),
456 				  !!(spi->mode & SPI_CS_HIGH));
457 	return 0;
458 }
459 
460 static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
461 				  void (*tx_fifo)(struct sh_msiof_spi_priv *,
462 						  const void *, int, int),
463 				  void (*rx_fifo)(struct sh_msiof_spi_priv *,
464 						  void *, int, int),
465 				  const void *tx_buf, void *rx_buf,
466 				  int words, int bits)
467 {
468 	int fifo_shift;
469 	int ret;
470 
471 	/* limit maximum word transfer to rx/tx fifo size */
472 	if (tx_buf)
473 		words = min_t(int, words, p->tx_fifo_size);
474 	if (rx_buf)
475 		words = min_t(int, words, p->rx_fifo_size);
476 
477 	/* the fifo contents need shifting */
478 	fifo_shift = 32 - bits;
479 
480 	/* setup msiof transfer mode registers */
481 	sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);
482 
483 	/* write tx fifo */
484 	if (tx_buf)
485 		tx_fifo(p, tx_buf, words, fifo_shift);
486 
487 	/* setup clock and rx/tx signals */
488 	ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
489 	if (rx_buf)
490 		ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
491 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);
492 
493 	/* start by setting frame bit */
494 	reinit_completion(&p->done);
495 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
496 	if (ret) {
497 		dev_err(&p->pdev->dev, "failed to start hardware\n");
498 		goto err;
499 	}
500 
501 	/* wait for tx fifo to be emptied / rx fifo to be filled */
502 	wait_for_completion(&p->done);
503 
504 	/* read rx fifo */
505 	if (rx_buf)
506 		rx_fifo(p, rx_buf, words, fifo_shift);
507 
508 	/* clear status bits */
509 	sh_msiof_reset_str(p);
510 
511 	/* shut down frame, rx/tx and clock signals */
512 	ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
513 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
514 	if (rx_buf)
515 		ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
516 	ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
517 	if (ret) {
518 		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
519 		goto err;
520 	}
521 
522 	return words;
523 
524  err:
525 	sh_msiof_write(p, IER, 0);
526 	return ret;
527 }
528 
529 static int sh_msiof_transfer_one(struct spi_master *master,
530 				 struct spi_device *spi,
531 				 struct spi_transfer *t)
532 {
533 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
534 	void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
535 	void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
536 	int bits;
537 	int bytes_per_word;
538 	int bytes_done;
539 	int words;
540 	int n;
541 	bool swab;
542 
543 	bits = t->bits_per_word;
544 
545 	if (bits <= 8 && t->len > 15 && !(t->len & 3)) {
546 		bits = 32;
547 		swab = true;
548 	} else {
549 		swab = false;
550 	}
551 
552 	/* setup bytes per word and fifo read/write functions */
553 	if (bits <= 8) {
554 		bytes_per_word = 1;
555 		tx_fifo = sh_msiof_spi_write_fifo_8;
556 		rx_fifo = sh_msiof_spi_read_fifo_8;
557 	} else if (bits <= 16) {
558 		bytes_per_word = 2;
559 		if ((unsigned long)t->tx_buf & 0x01)
560 			tx_fifo = sh_msiof_spi_write_fifo_16u;
561 		else
562 			tx_fifo = sh_msiof_spi_write_fifo_16;
563 
564 		if ((unsigned long)t->rx_buf & 0x01)
565 			rx_fifo = sh_msiof_spi_read_fifo_16u;
566 		else
567 			rx_fifo = sh_msiof_spi_read_fifo_16;
568 	} else if (swab) {
569 		bytes_per_word = 4;
570 		if ((unsigned long)t->tx_buf & 0x03)
571 			tx_fifo = sh_msiof_spi_write_fifo_s32u;
572 		else
573 			tx_fifo = sh_msiof_spi_write_fifo_s32;
574 
575 		if ((unsigned long)t->rx_buf & 0x03)
576 			rx_fifo = sh_msiof_spi_read_fifo_s32u;
577 		else
578 			rx_fifo = sh_msiof_spi_read_fifo_s32;
579 	} else {
580 		bytes_per_word = 4;
581 		if ((unsigned long)t->tx_buf & 0x03)
582 			tx_fifo = sh_msiof_spi_write_fifo_32u;
583 		else
584 			tx_fifo = sh_msiof_spi_write_fifo_32;
585 
586 		if ((unsigned long)t->rx_buf & 0x03)
587 			rx_fifo = sh_msiof_spi_read_fifo_32u;
588 		else
589 			rx_fifo = sh_msiof_spi_read_fifo_32;
590 	}
591 
592 	/* setup clocks (clock already enabled in chipselect()) */
593 	sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk), t->speed_hz);
594 
595 	/* transfer in fifo sized chunks */
596 	words = t->len / bytes_per_word;
597 	bytes_done = 0;
598 
599 	while (bytes_done < t->len) {
600 		void *rx_buf = t->rx_buf ? t->rx_buf + bytes_done : NULL;
601 		const void *tx_buf = t->tx_buf ? t->tx_buf + bytes_done : NULL;
602 		n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo,
603 					   tx_buf,
604 					   rx_buf,
605 					   words, bits);
606 		if (n < 0)
607 			break;
608 
609 		bytes_done += n * bytes_per_word;
610 		words -= n;
611 	}
612 
613 	return 0;
614 }
615 
616 static const struct sh_msiof_chipdata sh_data = {
617 	.tx_fifo_size = 64,
618 	.rx_fifo_size = 64,
619 	.master_flags = 0,
620 };
621 
622 static const struct sh_msiof_chipdata r8a779x_data = {
623 	.tx_fifo_size = 64,
624 	.rx_fifo_size = 256,
625 	.master_flags = SPI_MASTER_MUST_TX,
626 };
627 
628 static const struct of_device_id sh_msiof_match[] = {
629 	{ .compatible = "renesas,sh-msiof",        .data = &sh_data },
630 	{ .compatible = "renesas,sh-mobile-msiof", .data = &sh_data },
631 	{ .compatible = "renesas,msiof-r8a7790",   .data = &r8a779x_data },
632 	{ .compatible = "renesas,msiof-r8a7791",   .data = &r8a779x_data },
633 	{},
634 };
635 MODULE_DEVICE_TABLE(of, sh_msiof_match);
636 
637 #ifdef CONFIG_OF
638 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
639 {
640 	struct sh_msiof_spi_info *info;
641 	struct device_node *np = dev->of_node;
642 	u32 num_cs = 1;
643 
644 	info = devm_kzalloc(dev, sizeof(struct sh_msiof_spi_info), GFP_KERNEL);
645 	if (!info) {
646 		dev_err(dev, "failed to allocate setup data\n");
647 		return NULL;
648 	}
649 
650 	/* Parse the MSIOF properties */
651 	of_property_read_u32(np, "num-cs", &num_cs);
652 	of_property_read_u32(np, "renesas,tx-fifo-size",
653 					&info->tx_fifo_override);
654 	of_property_read_u32(np, "renesas,rx-fifo-size",
655 					&info->rx_fifo_override);
656 
657 	info->num_chipselect = num_cs;
658 
659 	return info;
660 }
661 #else
662 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
663 {
664 	return NULL;
665 }
666 #endif
667 
668 static int sh_msiof_spi_probe(struct platform_device *pdev)
669 {
670 	struct resource	*r;
671 	struct spi_master *master;
672 	const struct of_device_id *of_id;
673 	struct sh_msiof_spi_priv *p;
674 	int i;
675 	int ret;
676 
677 	master = spi_alloc_master(&pdev->dev, sizeof(struct sh_msiof_spi_priv));
678 	if (master == NULL) {
679 		dev_err(&pdev->dev, "failed to allocate spi master\n");
680 		return -ENOMEM;
681 	}
682 
683 	p = spi_master_get_devdata(master);
684 
685 	platform_set_drvdata(pdev, p);
686 
687 	of_id = of_match_device(sh_msiof_match, &pdev->dev);
688 	if (of_id) {
689 		p->chipdata = of_id->data;
690 		p->info = sh_msiof_spi_parse_dt(&pdev->dev);
691 	} else {
692 		p->chipdata = (const void *)pdev->id_entry->driver_data;
693 		p->info = dev_get_platdata(&pdev->dev);
694 	}
695 
696 	if (!p->info) {
697 		dev_err(&pdev->dev, "failed to obtain device info\n");
698 		ret = -ENXIO;
699 		goto err1;
700 	}
701 
702 	init_completion(&p->done);
703 
704 	p->clk = devm_clk_get(&pdev->dev, NULL);
705 	if (IS_ERR(p->clk)) {
706 		dev_err(&pdev->dev, "cannot get clock\n");
707 		ret = PTR_ERR(p->clk);
708 		goto err1;
709 	}
710 
711 	i = platform_get_irq(pdev, 0);
712 	if (i < 0) {
713 		dev_err(&pdev->dev, "cannot get platform IRQ\n");
714 		ret = -ENOENT;
715 		goto err1;
716 	}
717 
718 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
719 	p->mapbase = devm_ioremap_resource(&pdev->dev, r);
720 	if (IS_ERR(p->mapbase)) {
721 		ret = PTR_ERR(p->mapbase);
722 		goto err1;
723 	}
724 
725 	ret = devm_request_irq(&pdev->dev, i, sh_msiof_spi_irq, 0,
726 			       dev_name(&pdev->dev), p);
727 	if (ret) {
728 		dev_err(&pdev->dev, "unable to request irq\n");
729 		goto err1;
730 	}
731 
732 	p->pdev = pdev;
733 	pm_runtime_enable(&pdev->dev);
734 
735 	/* Platform data may override FIFO sizes */
736 	p->tx_fifo_size = p->chipdata->tx_fifo_size;
737 	p->rx_fifo_size = p->chipdata->rx_fifo_size;
738 	if (p->info->tx_fifo_override)
739 		p->tx_fifo_size = p->info->tx_fifo_override;
740 	if (p->info->rx_fifo_override)
741 		p->rx_fifo_size = p->info->rx_fifo_override;
742 
743 	/* init master code */
744 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
745 	master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
746 	master->flags = p->chipdata->master_flags;
747 	master->bus_num = pdev->id;
748 	master->dev.of_node = pdev->dev.of_node;
749 	master->num_chipselect = p->info->num_chipselect;
750 	master->setup = sh_msiof_spi_setup;
751 	master->prepare_message = sh_msiof_prepare_message;
752 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32);
753 	master->auto_runtime_pm = true;
754 	master->transfer_one = sh_msiof_transfer_one;
755 
756 	ret = devm_spi_register_master(&pdev->dev, master);
757 	if (ret < 0) {
758 		dev_err(&pdev->dev, "spi_register_master error.\n");
759 		goto err2;
760 	}
761 
762 	return 0;
763 
764  err2:
765 	pm_runtime_disable(&pdev->dev);
766  err1:
767 	spi_master_put(master);
768 	return ret;
769 }
770 
771 static int sh_msiof_spi_remove(struct platform_device *pdev)
772 {
773 	pm_runtime_disable(&pdev->dev);
774 	return 0;
775 }
776 
777 static struct platform_device_id spi_driver_ids[] = {
778 	{ "spi_sh_msiof",	(kernel_ulong_t)&sh_data },
779 	{ "spi_r8a7790_msiof",	(kernel_ulong_t)&r8a779x_data },
780 	{ "spi_r8a7791_msiof",	(kernel_ulong_t)&r8a779x_data },
781 	{},
782 };
783 MODULE_DEVICE_TABLE(platform, spi_driver_ids);
784 
785 static struct platform_driver sh_msiof_spi_drv = {
786 	.probe		= sh_msiof_spi_probe,
787 	.remove		= sh_msiof_spi_remove,
788 	.id_table	= spi_driver_ids,
789 	.driver		= {
790 		.name		= "spi_sh_msiof",
791 		.owner		= THIS_MODULE,
792 		.of_match_table = of_match_ptr(sh_msiof_match),
793 	},
794 };
795 module_platform_driver(sh_msiof_spi_drv);
796 
797 MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
798 MODULE_AUTHOR("Magnus Damm");
799 MODULE_LICENSE("GPL v2");
800 MODULE_ALIAS("platform:spi_sh_msiof");
801