xref: /openbmc/linux/drivers/spi/spi-sh-msiof.c (revision 711aab1d)
1 /*
2  * SuperH MSIOF SPI Master Interface
3  *
4  * Copyright (c) 2009 Magnus Damm
5  * Copyright (C) 2014 Renesas Electronics Corporation
6  * Copyright (C) 2014-2017 Glider bvba
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  *
12  */
13 
14 #include <linux/bitmap.h>
15 #include <linux/clk.h>
16 #include <linux/completion.h>
17 #include <linux/delay.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/dmaengine.h>
20 #include <linux/err.h>
21 #include <linux/gpio.h>
22 #include <linux/interrupt.h>
23 #include <linux/io.h>
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/of.h>
27 #include <linux/of_device.h>
28 #include <linux/platform_device.h>
29 #include <linux/pm_runtime.h>
30 #include <linux/sh_dma.h>
31 
32 #include <linux/spi/sh_msiof.h>
33 #include <linux/spi/spi.h>
34 
35 #include <asm/unaligned.h>
36 
37 struct sh_msiof_chipdata {
38 	u16 tx_fifo_size;
39 	u16 rx_fifo_size;
40 	u16 master_flags;
41 	u16 min_div;
42 };
43 
44 struct sh_msiof_spi_priv {
45 	struct spi_master *master;
46 	void __iomem *mapbase;
47 	struct clk *clk;
48 	struct platform_device *pdev;
49 	struct sh_msiof_spi_info *info;
50 	struct completion done;
51 	unsigned int tx_fifo_size;
52 	unsigned int rx_fifo_size;
53 	unsigned int min_div;
54 	void *tx_dma_page;
55 	void *rx_dma_page;
56 	dma_addr_t tx_dma_addr;
57 	dma_addr_t rx_dma_addr;
58 	bool slave_aborted;
59 };
60 
61 #define TMDR1	0x00	/* Transmit Mode Register 1 */
62 #define TMDR2	0x04	/* Transmit Mode Register 2 */
63 #define TMDR3	0x08	/* Transmit Mode Register 3 */
64 #define RMDR1	0x10	/* Receive Mode Register 1 */
65 #define RMDR2	0x14	/* Receive Mode Register 2 */
66 #define RMDR3	0x18	/* Receive Mode Register 3 */
67 #define TSCR	0x20	/* Transmit Clock Select Register */
68 #define RSCR	0x22	/* Receive Clock Select Register (SH, A1, APE6) */
69 #define CTR	0x28	/* Control Register */
70 #define FCTR	0x30	/* FIFO Control Register */
71 #define STR	0x40	/* Status Register */
72 #define IER	0x44	/* Interrupt Enable Register */
73 #define TDR1	0x48	/* Transmit Control Data Register 1 (SH, A1) */
74 #define TDR2	0x4c	/* Transmit Control Data Register 2 (SH, A1) */
75 #define TFDR	0x50	/* Transmit FIFO Data Register */
76 #define RDR1	0x58	/* Receive Control Data Register 1 (SH, A1) */
77 #define RDR2	0x5c	/* Receive Control Data Register 2 (SH, A1) */
78 #define RFDR	0x60	/* Receive FIFO Data Register */
79 
80 /* TMDR1 and RMDR1 */
81 #define MDR1_TRMD	 0x80000000 /* Transfer Mode (1 = Master mode) */
82 #define MDR1_SYNCMD_MASK 0x30000000 /* SYNC Mode */
83 #define MDR1_SYNCMD_SPI	 0x20000000 /*   Level mode/SPI */
84 #define MDR1_SYNCMD_LR	 0x30000000 /*   L/R mode */
85 #define MDR1_SYNCAC_SHIFT	 25 /* Sync Polarity (1 = Active-low) */
86 #define MDR1_BITLSB_SHIFT	 24 /* MSB/LSB First (1 = LSB first) */
87 #define MDR1_DTDL_SHIFT		 20 /* Data Pin Bit Delay for MSIOF_SYNC */
88 #define MDR1_SYNCDL_SHIFT	 16 /* Frame Sync Signal Timing Delay */
89 #define MDR1_FLD_MASK	 0x0000000c /* Frame Sync Signal Interval (0-3) */
90 #define MDR1_FLD_SHIFT		  2
91 #define MDR1_XXSTP	 0x00000001 /* Transmission/Reception Stop on FIFO */
92 /* TMDR1 */
93 #define TMDR1_PCON	 0x40000000 /* Transfer Signal Connection */
94 
95 /* TMDR2 and RMDR2 */
96 #define MDR2_BITLEN1(i)	(((i) - 1) << 24) /* Data Size (8-32 bits) */
97 #define MDR2_WDLEN1(i)	(((i) - 1) << 16) /* Word Count (1-64/256 (SH, A1))) */
98 #define MDR2_GRPMASK1	0x00000001 /* Group Output Mask 1 (SH, A1) */
99 
100 /* TSCR and RSCR */
101 #define SCR_BRPS_MASK	    0x1f00 /* Prescaler Setting (1-32) */
102 #define SCR_BRPS(i)	(((i) - 1) << 8)
103 #define SCR_BRDV_MASK	    0x0007 /* Baud Rate Generator's Division Ratio */
104 #define SCR_BRDV_DIV_2	    0x0000
105 #define SCR_BRDV_DIV_4	    0x0001
106 #define SCR_BRDV_DIV_8	    0x0002
107 #define SCR_BRDV_DIV_16	    0x0003
108 #define SCR_BRDV_DIV_32	    0x0004
109 #define SCR_BRDV_DIV_1	    0x0007
110 
111 /* CTR */
112 #define CTR_TSCKIZ_MASK	0xc0000000 /* Transmit Clock I/O Polarity Select */
113 #define CTR_TSCKIZ_SCK	0x80000000 /*   Disable SCK when TX disabled */
114 #define CTR_TSCKIZ_POL_SHIFT	30 /*   Transmit Clock Polarity */
115 #define CTR_RSCKIZ_MASK	0x30000000 /* Receive Clock Polarity Select */
116 #define CTR_RSCKIZ_SCK	0x20000000 /*   Must match CTR_TSCKIZ_SCK */
117 #define CTR_RSCKIZ_POL_SHIFT	28 /*   Receive Clock Polarity */
118 #define CTR_TEDG_SHIFT		27 /* Transmit Timing (1 = falling edge) */
119 #define CTR_REDG_SHIFT		26 /* Receive Timing (1 = falling edge) */
120 #define CTR_TXDIZ_MASK	0x00c00000 /* Pin Output When TX is Disabled */
121 #define CTR_TXDIZ_LOW	0x00000000 /*   0 */
122 #define CTR_TXDIZ_HIGH	0x00400000 /*   1 */
123 #define CTR_TXDIZ_HIZ	0x00800000 /*   High-impedance */
124 #define CTR_TSCKE	0x00008000 /* Transmit Serial Clock Output Enable */
125 #define CTR_TFSE	0x00004000 /* Transmit Frame Sync Signal Output Enable */
126 #define CTR_TXE		0x00000200 /* Transmit Enable */
127 #define CTR_RXE		0x00000100 /* Receive Enable */
128 
129 /* FCTR */
130 #define FCTR_TFWM_MASK	0xe0000000 /* Transmit FIFO Watermark */
131 #define FCTR_TFWM_64	0x00000000 /*  Transfer Request when 64 empty stages */
132 #define FCTR_TFWM_32	0x20000000 /*  Transfer Request when 32 empty stages */
133 #define FCTR_TFWM_24	0x40000000 /*  Transfer Request when 24 empty stages */
134 #define FCTR_TFWM_16	0x60000000 /*  Transfer Request when 16 empty stages */
135 #define FCTR_TFWM_12	0x80000000 /*  Transfer Request when 12 empty stages */
136 #define FCTR_TFWM_8	0xa0000000 /*  Transfer Request when 8 empty stages */
137 #define FCTR_TFWM_4	0xc0000000 /*  Transfer Request when 4 empty stages */
138 #define FCTR_TFWM_1	0xe0000000 /*  Transfer Request when 1 empty stage */
139 #define FCTR_TFUA_MASK	0x07f00000 /* Transmit FIFO Usable Area */
140 #define FCTR_TFUA_SHIFT		20
141 #define FCTR_TFUA(i)	((i) << FCTR_TFUA_SHIFT)
142 #define FCTR_RFWM_MASK	0x0000e000 /* Receive FIFO Watermark */
143 #define FCTR_RFWM_1	0x00000000 /*  Transfer Request when 1 valid stages */
144 #define FCTR_RFWM_4	0x00002000 /*  Transfer Request when 4 valid stages */
145 #define FCTR_RFWM_8	0x00004000 /*  Transfer Request when 8 valid stages */
146 #define FCTR_RFWM_16	0x00006000 /*  Transfer Request when 16 valid stages */
147 #define FCTR_RFWM_32	0x00008000 /*  Transfer Request when 32 valid stages */
148 #define FCTR_RFWM_64	0x0000a000 /*  Transfer Request when 64 valid stages */
149 #define FCTR_RFWM_128	0x0000c000 /*  Transfer Request when 128 valid stages */
150 #define FCTR_RFWM_256	0x0000e000 /*  Transfer Request when 256 valid stages */
151 #define FCTR_RFUA_MASK	0x00001ff0 /* Receive FIFO Usable Area (0x40 = full) */
152 #define FCTR_RFUA_SHIFT		 4
153 #define FCTR_RFUA(i)	((i) << FCTR_RFUA_SHIFT)
154 
155 /* STR */
156 #define STR_TFEMP	0x20000000 /* Transmit FIFO Empty */
157 #define STR_TDREQ	0x10000000 /* Transmit Data Transfer Request */
158 #define STR_TEOF	0x00800000 /* Frame Transmission End */
159 #define STR_TFSERR	0x00200000 /* Transmit Frame Synchronization Error */
160 #define STR_TFOVF	0x00100000 /* Transmit FIFO Overflow */
161 #define STR_TFUDF	0x00080000 /* Transmit FIFO Underflow */
162 #define STR_RFFUL	0x00002000 /* Receive FIFO Full */
163 #define STR_RDREQ	0x00001000 /* Receive Data Transfer Request */
164 #define STR_REOF	0x00000080 /* Frame Reception End */
165 #define STR_RFSERR	0x00000020 /* Receive Frame Synchronization Error */
166 #define STR_RFUDF	0x00000010 /* Receive FIFO Underflow */
167 #define STR_RFOVF	0x00000008 /* Receive FIFO Overflow */
168 
169 /* IER */
170 #define IER_TDMAE	0x80000000 /* Transmit Data DMA Transfer Req. Enable */
171 #define IER_TFEMPE	0x20000000 /* Transmit FIFO Empty Enable */
172 #define IER_TDREQE	0x10000000 /* Transmit Data Transfer Request Enable */
173 #define IER_TEOFE	0x00800000 /* Frame Transmission End Enable */
174 #define IER_TFSERRE	0x00200000 /* Transmit Frame Sync Error Enable */
175 #define IER_TFOVFE	0x00100000 /* Transmit FIFO Overflow Enable */
176 #define IER_TFUDFE	0x00080000 /* Transmit FIFO Underflow Enable */
177 #define IER_RDMAE	0x00008000 /* Receive Data DMA Transfer Req. Enable */
178 #define IER_RFFULE	0x00002000 /* Receive FIFO Full Enable */
179 #define IER_RDREQE	0x00001000 /* Receive Data Transfer Request Enable */
180 #define IER_REOFE	0x00000080 /* Frame Reception End Enable */
181 #define IER_RFSERRE	0x00000020 /* Receive Frame Sync Error Enable */
182 #define IER_RFUDFE	0x00000010 /* Receive FIFO Underflow Enable */
183 #define IER_RFOVFE	0x00000008 /* Receive FIFO Overflow Enable */
184 
185 
186 static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs)
187 {
188 	switch (reg_offs) {
189 	case TSCR:
190 	case RSCR:
191 		return ioread16(p->mapbase + reg_offs);
192 	default:
193 		return ioread32(p->mapbase + reg_offs);
194 	}
195 }
196 
197 static void sh_msiof_write(struct sh_msiof_spi_priv *p, int reg_offs,
198 			   u32 value)
199 {
200 	switch (reg_offs) {
201 	case TSCR:
202 	case RSCR:
203 		iowrite16(value, p->mapbase + reg_offs);
204 		break;
205 	default:
206 		iowrite32(value, p->mapbase + reg_offs);
207 		break;
208 	}
209 }
210 
211 static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv *p,
212 				    u32 clr, u32 set)
213 {
214 	u32 mask = clr | set;
215 	u32 data;
216 	int k;
217 
218 	data = sh_msiof_read(p, CTR);
219 	data &= ~clr;
220 	data |= set;
221 	sh_msiof_write(p, CTR, data);
222 
223 	for (k = 100; k > 0; k--) {
224 		if ((sh_msiof_read(p, CTR) & mask) == set)
225 			break;
226 
227 		udelay(10);
228 	}
229 
230 	return k > 0 ? 0 : -ETIMEDOUT;
231 }
232 
233 static irqreturn_t sh_msiof_spi_irq(int irq, void *data)
234 {
235 	struct sh_msiof_spi_priv *p = data;
236 
237 	/* just disable the interrupt and wake up */
238 	sh_msiof_write(p, IER, 0);
239 	complete(&p->done);
240 
241 	return IRQ_HANDLED;
242 }
243 
244 static struct {
245 	unsigned short div;
246 	unsigned short brdv;
247 } const sh_msiof_spi_div_table[] = {
248 	{ 1,	SCR_BRDV_DIV_1 },
249 	{ 2,	SCR_BRDV_DIV_2 },
250 	{ 4,	SCR_BRDV_DIV_4 },
251 	{ 8,	SCR_BRDV_DIV_8 },
252 	{ 16,	SCR_BRDV_DIV_16 },
253 	{ 32,	SCR_BRDV_DIV_32 },
254 };
255 
256 static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
257 				      unsigned long parent_rate, u32 spi_hz)
258 {
259 	unsigned long div = 1024;
260 	u32 brps, scr;
261 	size_t k;
262 
263 	if (!WARN_ON(!spi_hz || !parent_rate))
264 		div = DIV_ROUND_UP(parent_rate, spi_hz);
265 
266 	div = max_t(unsigned long, div, p->min_div);
267 
268 	for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_div_table); k++) {
269 		brps = DIV_ROUND_UP(div, sh_msiof_spi_div_table[k].div);
270 		/* SCR_BRDV_DIV_1 is valid only if BRPS is x 1/1 or x 1/2 */
271 		if (sh_msiof_spi_div_table[k].div == 1 && brps > 2)
272 			continue;
273 		if (brps <= 32) /* max of brdv is 32 */
274 			break;
275 	}
276 
277 	k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_div_table) - 1);
278 
279 	scr = sh_msiof_spi_div_table[k].brdv | SCR_BRPS(brps);
280 	sh_msiof_write(p, TSCR, scr);
281 	if (!(p->master->flags & SPI_MASTER_MUST_TX))
282 		sh_msiof_write(p, RSCR, scr);
283 }
284 
285 static u32 sh_msiof_get_delay_bit(u32 dtdl_or_syncdl)
286 {
287 	/*
288 	 * DTDL/SYNCDL bit	: p->info->dtdl or p->info->syncdl
289 	 * b'000		: 0
290 	 * b'001		: 100
291 	 * b'010		: 200
292 	 * b'011 (SYNCDL only)	: 300
293 	 * b'101		: 50
294 	 * b'110		: 150
295 	 */
296 	if (dtdl_or_syncdl % 100)
297 		return dtdl_or_syncdl / 100 + 5;
298 	else
299 		return dtdl_or_syncdl / 100;
300 }
301 
302 static u32 sh_msiof_spi_get_dtdl_and_syncdl(struct sh_msiof_spi_priv *p)
303 {
304 	u32 val;
305 
306 	if (!p->info)
307 		return 0;
308 
309 	/* check if DTDL and SYNCDL is allowed value */
310 	if (p->info->dtdl > 200 || p->info->syncdl > 300) {
311 		dev_warn(&p->pdev->dev, "DTDL or SYNCDL is too large\n");
312 		return 0;
313 	}
314 
315 	/* check if the sum of DTDL and SYNCDL becomes an integer value  */
316 	if ((p->info->dtdl + p->info->syncdl) % 100) {
317 		dev_warn(&p->pdev->dev, "the sum of DTDL/SYNCDL is not good\n");
318 		return 0;
319 	}
320 
321 	val = sh_msiof_get_delay_bit(p->info->dtdl) << MDR1_DTDL_SHIFT;
322 	val |= sh_msiof_get_delay_bit(p->info->syncdl) << MDR1_SYNCDL_SHIFT;
323 
324 	return val;
325 }
326 
327 static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
328 				      u32 cpol, u32 cpha,
329 				      u32 tx_hi_z, u32 lsb_first, u32 cs_high)
330 {
331 	u32 tmp;
332 	int edge;
333 
334 	/*
335 	 * CPOL CPHA     TSCKIZ RSCKIZ TEDG REDG
336 	 *    0    0         10     10    1    1
337 	 *    0    1         10     10    0    0
338 	 *    1    0         11     11    0    0
339 	 *    1    1         11     11    1    1
340 	 */
341 	tmp = MDR1_SYNCMD_SPI | 1 << MDR1_FLD_SHIFT | MDR1_XXSTP;
342 	tmp |= !cs_high << MDR1_SYNCAC_SHIFT;
343 	tmp |= lsb_first << MDR1_BITLSB_SHIFT;
344 	tmp |= sh_msiof_spi_get_dtdl_and_syncdl(p);
345 	if (spi_controller_is_slave(p->master))
346 		sh_msiof_write(p, TMDR1, tmp | TMDR1_PCON);
347 	else
348 		sh_msiof_write(p, TMDR1, tmp | MDR1_TRMD | TMDR1_PCON);
349 	if (p->master->flags & SPI_MASTER_MUST_TX) {
350 		/* These bits are reserved if RX needs TX */
351 		tmp &= ~0x0000ffff;
352 	}
353 	sh_msiof_write(p, RMDR1, tmp);
354 
355 	tmp = 0;
356 	tmp |= CTR_TSCKIZ_SCK | cpol << CTR_TSCKIZ_POL_SHIFT;
357 	tmp |= CTR_RSCKIZ_SCK | cpol << CTR_RSCKIZ_POL_SHIFT;
358 
359 	edge = cpol ^ !cpha;
360 
361 	tmp |= edge << CTR_TEDG_SHIFT;
362 	tmp |= edge << CTR_REDG_SHIFT;
363 	tmp |= tx_hi_z ? CTR_TXDIZ_HIZ : CTR_TXDIZ_LOW;
364 	sh_msiof_write(p, CTR, tmp);
365 }
366 
367 static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
368 				       const void *tx_buf, void *rx_buf,
369 				       u32 bits, u32 words)
370 {
371 	u32 dr2 = MDR2_BITLEN1(bits) | MDR2_WDLEN1(words);
372 
373 	if (tx_buf || (p->master->flags & SPI_MASTER_MUST_TX))
374 		sh_msiof_write(p, TMDR2, dr2);
375 	else
376 		sh_msiof_write(p, TMDR2, dr2 | MDR2_GRPMASK1);
377 
378 	if (rx_buf)
379 		sh_msiof_write(p, RMDR2, dr2);
380 }
381 
382 static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
383 {
384 	sh_msiof_write(p, STR, sh_msiof_read(p, STR));
385 }
386 
387 static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
388 				      const void *tx_buf, int words, int fs)
389 {
390 	const u8 *buf_8 = tx_buf;
391 	int k;
392 
393 	for (k = 0; k < words; k++)
394 		sh_msiof_write(p, TFDR, buf_8[k] << fs);
395 }
396 
397 static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
398 				       const void *tx_buf, int words, int fs)
399 {
400 	const u16 *buf_16 = tx_buf;
401 	int k;
402 
403 	for (k = 0; k < words; k++)
404 		sh_msiof_write(p, TFDR, buf_16[k] << fs);
405 }
406 
407 static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
408 					const void *tx_buf, int words, int fs)
409 {
410 	const u16 *buf_16 = tx_buf;
411 	int k;
412 
413 	for (k = 0; k < words; k++)
414 		sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
415 }
416 
417 static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
418 				       const void *tx_buf, int words, int fs)
419 {
420 	const u32 *buf_32 = tx_buf;
421 	int k;
422 
423 	for (k = 0; k < words; k++)
424 		sh_msiof_write(p, TFDR, buf_32[k] << fs);
425 }
426 
427 static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
428 					const void *tx_buf, int words, int fs)
429 {
430 	const u32 *buf_32 = tx_buf;
431 	int k;
432 
433 	for (k = 0; k < words; k++)
434 		sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
435 }
436 
437 static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
438 					const void *tx_buf, int words, int fs)
439 {
440 	const u32 *buf_32 = tx_buf;
441 	int k;
442 
443 	for (k = 0; k < words; k++)
444 		sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
445 }
446 
447 static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
448 					 const void *tx_buf, int words, int fs)
449 {
450 	const u32 *buf_32 = tx_buf;
451 	int k;
452 
453 	for (k = 0; k < words; k++)
454 		sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
455 }
456 
457 static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
458 				     void *rx_buf, int words, int fs)
459 {
460 	u8 *buf_8 = rx_buf;
461 	int k;
462 
463 	for (k = 0; k < words; k++)
464 		buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
465 }
466 
467 static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
468 				      void *rx_buf, int words, int fs)
469 {
470 	u16 *buf_16 = rx_buf;
471 	int k;
472 
473 	for (k = 0; k < words; k++)
474 		buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
475 }
476 
477 static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
478 				       void *rx_buf, int words, int fs)
479 {
480 	u16 *buf_16 = rx_buf;
481 	int k;
482 
483 	for (k = 0; k < words; k++)
484 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
485 }
486 
487 static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
488 				      void *rx_buf, int words, int fs)
489 {
490 	u32 *buf_32 = rx_buf;
491 	int k;
492 
493 	for (k = 0; k < words; k++)
494 		buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
495 }
496 
497 static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
498 				       void *rx_buf, int words, int fs)
499 {
500 	u32 *buf_32 = rx_buf;
501 	int k;
502 
503 	for (k = 0; k < words; k++)
504 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
505 }
506 
507 static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
508 				       void *rx_buf, int words, int fs)
509 {
510 	u32 *buf_32 = rx_buf;
511 	int k;
512 
513 	for (k = 0; k < words; k++)
514 		buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
515 }
516 
517 static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
518 				       void *rx_buf, int words, int fs)
519 {
520 	u32 *buf_32 = rx_buf;
521 	int k;
522 
523 	for (k = 0; k < words; k++)
524 		put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
525 }
526 
527 static int sh_msiof_spi_setup(struct spi_device *spi)
528 {
529 	struct device_node	*np = spi->master->dev.of_node;
530 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
531 
532 	pm_runtime_get_sync(&p->pdev->dev);
533 
534 	if (!np) {
535 		/*
536 		 * Use spi->controller_data for CS (same strategy as spi_gpio),
537 		 * if any. otherwise let HW control CS
538 		 */
539 		spi->cs_gpio = (uintptr_t)spi->controller_data;
540 	}
541 
542 	/* Configure pins before deasserting CS */
543 	sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
544 				  !!(spi->mode & SPI_CPHA),
545 				  !!(spi->mode & SPI_3WIRE),
546 				  !!(spi->mode & SPI_LSB_FIRST),
547 				  !!(spi->mode & SPI_CS_HIGH));
548 
549 	if (spi->cs_gpio >= 0)
550 		gpio_set_value(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
551 
552 
553 	pm_runtime_put(&p->pdev->dev);
554 
555 	return 0;
556 }
557 
558 static int sh_msiof_prepare_message(struct spi_master *master,
559 				    struct spi_message *msg)
560 {
561 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
562 	const struct spi_device *spi = msg->spi;
563 
564 	/* Configure pins before asserting CS */
565 	sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
566 				  !!(spi->mode & SPI_CPHA),
567 				  !!(spi->mode & SPI_3WIRE),
568 				  !!(spi->mode & SPI_LSB_FIRST),
569 				  !!(spi->mode & SPI_CS_HIGH));
570 	return 0;
571 }
572 
573 static int sh_msiof_spi_start(struct sh_msiof_spi_priv *p, void *rx_buf)
574 {
575 	bool slave = spi_controller_is_slave(p->master);
576 	int ret = 0;
577 
578 	/* setup clock and rx/tx signals */
579 	if (!slave)
580 		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
581 	if (rx_buf && !ret)
582 		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
583 	if (!ret)
584 		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);
585 
586 	/* start by setting frame bit */
587 	if (!ret && !slave)
588 		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
589 
590 	return ret;
591 }
592 
593 static int sh_msiof_spi_stop(struct sh_msiof_spi_priv *p, void *rx_buf)
594 {
595 	bool slave = spi_controller_is_slave(p->master);
596 	int ret = 0;
597 
598 	/* shut down frame, rx/tx and clock signals */
599 	if (!slave)
600 		ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
601 	if (!ret)
602 		ret = sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
603 	if (rx_buf && !ret)
604 		ret = sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
605 	if (!ret && !slave)
606 		ret = sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
607 
608 	return ret;
609 }
610 
611 static int sh_msiof_slave_abort(struct spi_master *master)
612 {
613 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
614 
615 	p->slave_aborted = true;
616 	complete(&p->done);
617 	return 0;
618 }
619 
620 static int sh_msiof_wait_for_completion(struct sh_msiof_spi_priv *p)
621 {
622 	if (spi_controller_is_slave(p->master)) {
623 		if (wait_for_completion_interruptible(&p->done) ||
624 		    p->slave_aborted) {
625 			dev_dbg(&p->pdev->dev, "interrupted\n");
626 			return -EINTR;
627 		}
628 	} else {
629 		if (!wait_for_completion_timeout(&p->done, HZ)) {
630 			dev_err(&p->pdev->dev, "timeout\n");
631 			return -ETIMEDOUT;
632 		}
633 	}
634 
635 	return 0;
636 }
637 
638 static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
639 				  void (*tx_fifo)(struct sh_msiof_spi_priv *,
640 						  const void *, int, int),
641 				  void (*rx_fifo)(struct sh_msiof_spi_priv *,
642 						  void *, int, int),
643 				  const void *tx_buf, void *rx_buf,
644 				  int words, int bits)
645 {
646 	int fifo_shift;
647 	int ret;
648 
649 	/* limit maximum word transfer to rx/tx fifo size */
650 	if (tx_buf)
651 		words = min_t(int, words, p->tx_fifo_size);
652 	if (rx_buf)
653 		words = min_t(int, words, p->rx_fifo_size);
654 
655 	/* the fifo contents need shifting */
656 	fifo_shift = 32 - bits;
657 
658 	/* default FIFO watermarks for PIO */
659 	sh_msiof_write(p, FCTR, 0);
660 
661 	/* setup msiof transfer mode registers */
662 	sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);
663 	sh_msiof_write(p, IER, IER_TEOFE | IER_REOFE);
664 
665 	/* write tx fifo */
666 	if (tx_buf)
667 		tx_fifo(p, tx_buf, words, fifo_shift);
668 
669 	reinit_completion(&p->done);
670 	p->slave_aborted = false;
671 
672 	ret = sh_msiof_spi_start(p, rx_buf);
673 	if (ret) {
674 		dev_err(&p->pdev->dev, "failed to start hardware\n");
675 		goto stop_ier;
676 	}
677 
678 	/* wait for tx fifo to be emptied / rx fifo to be filled */
679 	ret = sh_msiof_wait_for_completion(p);
680 	if (ret)
681 		goto stop_reset;
682 
683 	/* read rx fifo */
684 	if (rx_buf)
685 		rx_fifo(p, rx_buf, words, fifo_shift);
686 
687 	/* clear status bits */
688 	sh_msiof_reset_str(p);
689 
690 	ret = sh_msiof_spi_stop(p, rx_buf);
691 	if (ret) {
692 		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
693 		return ret;
694 	}
695 
696 	return words;
697 
698 stop_reset:
699 	sh_msiof_reset_str(p);
700 	sh_msiof_spi_stop(p, rx_buf);
701 stop_ier:
702 	sh_msiof_write(p, IER, 0);
703 	return ret;
704 }
705 
706 static void sh_msiof_dma_complete(void *arg)
707 {
708 	struct sh_msiof_spi_priv *p = arg;
709 
710 	sh_msiof_write(p, IER, 0);
711 	complete(&p->done);
712 }
713 
714 static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
715 			     void *rx, unsigned int len)
716 {
717 	u32 ier_bits = 0;
718 	struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
719 	dma_cookie_t cookie;
720 	int ret;
721 
722 	/* First prepare and submit the DMA request(s), as this may fail */
723 	if (rx) {
724 		ier_bits |= IER_RDREQE | IER_RDMAE;
725 		desc_rx = dmaengine_prep_slave_single(p->master->dma_rx,
726 					p->rx_dma_addr, len, DMA_FROM_DEVICE,
727 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
728 		if (!desc_rx)
729 			return -EAGAIN;
730 
731 		desc_rx->callback = sh_msiof_dma_complete;
732 		desc_rx->callback_param = p;
733 		cookie = dmaengine_submit(desc_rx);
734 		if (dma_submit_error(cookie))
735 			return cookie;
736 	}
737 
738 	if (tx) {
739 		ier_bits |= IER_TDREQE | IER_TDMAE;
740 		dma_sync_single_for_device(p->master->dma_tx->device->dev,
741 					   p->tx_dma_addr, len, DMA_TO_DEVICE);
742 		desc_tx = dmaengine_prep_slave_single(p->master->dma_tx,
743 					p->tx_dma_addr, len, DMA_TO_DEVICE,
744 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
745 		if (!desc_tx) {
746 			ret = -EAGAIN;
747 			goto no_dma_tx;
748 		}
749 
750 		if (rx) {
751 			/* No callback */
752 			desc_tx->callback = NULL;
753 		} else {
754 			desc_tx->callback = sh_msiof_dma_complete;
755 			desc_tx->callback_param = p;
756 		}
757 		cookie = dmaengine_submit(desc_tx);
758 		if (dma_submit_error(cookie)) {
759 			ret = cookie;
760 			goto no_dma_tx;
761 		}
762 	}
763 
764 	/* 1 stage FIFO watermarks for DMA */
765 	sh_msiof_write(p, FCTR, FCTR_TFWM_1 | FCTR_RFWM_1);
766 
767 	/* setup msiof transfer mode registers (32-bit words) */
768 	sh_msiof_spi_set_mode_regs(p, tx, rx, 32, len / 4);
769 
770 	sh_msiof_write(p, IER, ier_bits);
771 
772 	reinit_completion(&p->done);
773 	p->slave_aborted = false;
774 
775 	/* Now start DMA */
776 	if (rx)
777 		dma_async_issue_pending(p->master->dma_rx);
778 	if (tx)
779 		dma_async_issue_pending(p->master->dma_tx);
780 
781 	ret = sh_msiof_spi_start(p, rx);
782 	if (ret) {
783 		dev_err(&p->pdev->dev, "failed to start hardware\n");
784 		goto stop_dma;
785 	}
786 
787 	/* wait for tx fifo to be emptied / rx fifo to be filled */
788 	ret = sh_msiof_wait_for_completion(p);
789 	if (ret)
790 		goto stop_reset;
791 
792 	/* clear status bits */
793 	sh_msiof_reset_str(p);
794 
795 	ret = sh_msiof_spi_stop(p, rx);
796 	if (ret) {
797 		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
798 		return ret;
799 	}
800 
801 	if (rx)
802 		dma_sync_single_for_cpu(p->master->dma_rx->device->dev,
803 					p->rx_dma_addr, len,
804 					DMA_FROM_DEVICE);
805 
806 	return 0;
807 
808 stop_reset:
809 	sh_msiof_reset_str(p);
810 	sh_msiof_spi_stop(p, rx);
811 stop_dma:
812 	if (tx)
813 		dmaengine_terminate_all(p->master->dma_tx);
814 no_dma_tx:
815 	if (rx)
816 		dmaengine_terminate_all(p->master->dma_rx);
817 	sh_msiof_write(p, IER, 0);
818 	return ret;
819 }
820 
821 static void copy_bswap32(u32 *dst, const u32 *src, unsigned int words)
822 {
823 	/* src or dst can be unaligned, but not both */
824 	if ((unsigned long)src & 3) {
825 		while (words--) {
826 			*dst++ = swab32(get_unaligned(src));
827 			src++;
828 		}
829 	} else if ((unsigned long)dst & 3) {
830 		while (words--) {
831 			put_unaligned(swab32(*src++), dst);
832 			dst++;
833 		}
834 	} else {
835 		while (words--)
836 			*dst++ = swab32(*src++);
837 	}
838 }
839 
840 static void copy_wswap32(u32 *dst, const u32 *src, unsigned int words)
841 {
842 	/* src or dst can be unaligned, but not both */
843 	if ((unsigned long)src & 3) {
844 		while (words--) {
845 			*dst++ = swahw32(get_unaligned(src));
846 			src++;
847 		}
848 	} else if ((unsigned long)dst & 3) {
849 		while (words--) {
850 			put_unaligned(swahw32(*src++), dst);
851 			dst++;
852 		}
853 	} else {
854 		while (words--)
855 			*dst++ = swahw32(*src++);
856 	}
857 }
858 
859 static void copy_plain32(u32 *dst, const u32 *src, unsigned int words)
860 {
861 	memcpy(dst, src, words * 4);
862 }
863 
864 static int sh_msiof_transfer_one(struct spi_master *master,
865 				 struct spi_device *spi,
866 				 struct spi_transfer *t)
867 {
868 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
869 	void (*copy32)(u32 *, const u32 *, unsigned int);
870 	void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
871 	void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
872 	const void *tx_buf = t->tx_buf;
873 	void *rx_buf = t->rx_buf;
874 	unsigned int len = t->len;
875 	unsigned int bits = t->bits_per_word;
876 	unsigned int bytes_per_word;
877 	unsigned int words;
878 	int n;
879 	bool swab;
880 	int ret;
881 
882 	/* setup clocks (clock already enabled in chipselect()) */
883 	if (!spi_controller_is_slave(p->master))
884 		sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk), t->speed_hz);
885 
886 	while (master->dma_tx && len > 15) {
887 		/*
888 		 *  DMA supports 32-bit words only, hence pack 8-bit and 16-bit
889 		 *  words, with byte resp. word swapping.
890 		 */
891 		unsigned int l = 0;
892 
893 		if (tx_buf)
894 			l = min(len, p->tx_fifo_size * 4);
895 		if (rx_buf)
896 			l = min(len, p->rx_fifo_size * 4);
897 
898 		if (bits <= 8) {
899 			if (l & 3)
900 				break;
901 			copy32 = copy_bswap32;
902 		} else if (bits <= 16) {
903 			if (l & 1)
904 				break;
905 			copy32 = copy_wswap32;
906 		} else {
907 			copy32 = copy_plain32;
908 		}
909 
910 		if (tx_buf)
911 			copy32(p->tx_dma_page, tx_buf, l / 4);
912 
913 		ret = sh_msiof_dma_once(p, tx_buf, rx_buf, l);
914 		if (ret == -EAGAIN) {
915 			pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
916 				     dev_driver_string(&p->pdev->dev),
917 				     dev_name(&p->pdev->dev));
918 			break;
919 		}
920 		if (ret)
921 			return ret;
922 
923 		if (rx_buf) {
924 			copy32(rx_buf, p->rx_dma_page, l / 4);
925 			rx_buf += l;
926 		}
927 		if (tx_buf)
928 			tx_buf += l;
929 
930 		len -= l;
931 		if (!len)
932 			return 0;
933 	}
934 
935 	if (bits <= 8 && len > 15 && !(len & 3)) {
936 		bits = 32;
937 		swab = true;
938 	} else {
939 		swab = false;
940 	}
941 
942 	/* setup bytes per word and fifo read/write functions */
943 	if (bits <= 8) {
944 		bytes_per_word = 1;
945 		tx_fifo = sh_msiof_spi_write_fifo_8;
946 		rx_fifo = sh_msiof_spi_read_fifo_8;
947 	} else if (bits <= 16) {
948 		bytes_per_word = 2;
949 		if ((unsigned long)tx_buf & 0x01)
950 			tx_fifo = sh_msiof_spi_write_fifo_16u;
951 		else
952 			tx_fifo = sh_msiof_spi_write_fifo_16;
953 
954 		if ((unsigned long)rx_buf & 0x01)
955 			rx_fifo = sh_msiof_spi_read_fifo_16u;
956 		else
957 			rx_fifo = sh_msiof_spi_read_fifo_16;
958 	} else if (swab) {
959 		bytes_per_word = 4;
960 		if ((unsigned long)tx_buf & 0x03)
961 			tx_fifo = sh_msiof_spi_write_fifo_s32u;
962 		else
963 			tx_fifo = sh_msiof_spi_write_fifo_s32;
964 
965 		if ((unsigned long)rx_buf & 0x03)
966 			rx_fifo = sh_msiof_spi_read_fifo_s32u;
967 		else
968 			rx_fifo = sh_msiof_spi_read_fifo_s32;
969 	} else {
970 		bytes_per_word = 4;
971 		if ((unsigned long)tx_buf & 0x03)
972 			tx_fifo = sh_msiof_spi_write_fifo_32u;
973 		else
974 			tx_fifo = sh_msiof_spi_write_fifo_32;
975 
976 		if ((unsigned long)rx_buf & 0x03)
977 			rx_fifo = sh_msiof_spi_read_fifo_32u;
978 		else
979 			rx_fifo = sh_msiof_spi_read_fifo_32;
980 	}
981 
982 	/* transfer in fifo sized chunks */
983 	words = len / bytes_per_word;
984 
985 	while (words > 0) {
986 		n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo, tx_buf, rx_buf,
987 					   words, bits);
988 		if (n < 0)
989 			return n;
990 
991 		if (tx_buf)
992 			tx_buf += n * bytes_per_word;
993 		if (rx_buf)
994 			rx_buf += n * bytes_per_word;
995 		words -= n;
996 	}
997 
998 	return 0;
999 }
1000 
1001 static const struct sh_msiof_chipdata sh_data = {
1002 	.tx_fifo_size = 64,
1003 	.rx_fifo_size = 64,
1004 	.master_flags = 0,
1005 	.min_div = 1,
1006 };
1007 
1008 static const struct sh_msiof_chipdata rcar_gen2_data = {
1009 	.tx_fifo_size = 64,
1010 	.rx_fifo_size = 64,
1011 	.master_flags = SPI_MASTER_MUST_TX,
1012 	.min_div = 1,
1013 };
1014 
1015 static const struct sh_msiof_chipdata rcar_gen3_data = {
1016 	.tx_fifo_size = 64,
1017 	.rx_fifo_size = 64,
1018 	.master_flags = SPI_MASTER_MUST_TX,
1019 	.min_div = 2,
1020 };
1021 
1022 static const struct of_device_id sh_msiof_match[] = {
1023 	{ .compatible = "renesas,sh-mobile-msiof", .data = &sh_data },
1024 	{ .compatible = "renesas,msiof-r8a7790",   .data = &rcar_gen2_data },
1025 	{ .compatible = "renesas,msiof-r8a7791",   .data = &rcar_gen2_data },
1026 	{ .compatible = "renesas,msiof-r8a7792",   .data = &rcar_gen2_data },
1027 	{ .compatible = "renesas,msiof-r8a7793",   .data = &rcar_gen2_data },
1028 	{ .compatible = "renesas,msiof-r8a7794",   .data = &rcar_gen2_data },
1029 	{ .compatible = "renesas,rcar-gen2-msiof", .data = &rcar_gen2_data },
1030 	{ .compatible = "renesas,msiof-r8a7796",   .data = &rcar_gen3_data },
1031 	{ .compatible = "renesas,rcar-gen3-msiof", .data = &rcar_gen3_data },
1032 	{ .compatible = "renesas,sh-msiof",        .data = &sh_data }, /* Deprecated */
1033 	{},
1034 };
1035 MODULE_DEVICE_TABLE(of, sh_msiof_match);
1036 
1037 #ifdef CONFIG_OF
1038 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
1039 {
1040 	struct sh_msiof_spi_info *info;
1041 	struct device_node *np = dev->of_node;
1042 	u32 num_cs = 1;
1043 
1044 	info = devm_kzalloc(dev, sizeof(struct sh_msiof_spi_info), GFP_KERNEL);
1045 	if (!info)
1046 		return NULL;
1047 
1048 	info->mode = of_property_read_bool(np, "spi-slave") ? MSIOF_SPI_SLAVE
1049 							    : MSIOF_SPI_MASTER;
1050 
1051 	/* Parse the MSIOF properties */
1052 	if (info->mode == MSIOF_SPI_MASTER)
1053 		of_property_read_u32(np, "num-cs", &num_cs);
1054 	of_property_read_u32(np, "renesas,tx-fifo-size",
1055 					&info->tx_fifo_override);
1056 	of_property_read_u32(np, "renesas,rx-fifo-size",
1057 					&info->rx_fifo_override);
1058 	of_property_read_u32(np, "renesas,dtdl", &info->dtdl);
1059 	of_property_read_u32(np, "renesas,syncdl", &info->syncdl);
1060 
1061 	info->num_chipselect = num_cs;
1062 
1063 	return info;
1064 }
1065 #else
1066 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
1067 {
1068 	return NULL;
1069 }
1070 #endif
1071 
1072 static struct dma_chan *sh_msiof_request_dma_chan(struct device *dev,
1073 	enum dma_transfer_direction dir, unsigned int id, dma_addr_t port_addr)
1074 {
1075 	dma_cap_mask_t mask;
1076 	struct dma_chan *chan;
1077 	struct dma_slave_config cfg;
1078 	int ret;
1079 
1080 	dma_cap_zero(mask);
1081 	dma_cap_set(DMA_SLAVE, mask);
1082 
1083 	chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
1084 				(void *)(unsigned long)id, dev,
1085 				dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1086 	if (!chan) {
1087 		dev_warn(dev, "dma_request_slave_channel_compat failed\n");
1088 		return NULL;
1089 	}
1090 
1091 	memset(&cfg, 0, sizeof(cfg));
1092 	cfg.direction = dir;
1093 	if (dir == DMA_MEM_TO_DEV) {
1094 		cfg.dst_addr = port_addr;
1095 		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1096 	} else {
1097 		cfg.src_addr = port_addr;
1098 		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1099 	}
1100 
1101 	ret = dmaengine_slave_config(chan, &cfg);
1102 	if (ret) {
1103 		dev_warn(dev, "dmaengine_slave_config failed %d\n", ret);
1104 		dma_release_channel(chan);
1105 		return NULL;
1106 	}
1107 
1108 	return chan;
1109 }
1110 
1111 static int sh_msiof_request_dma(struct sh_msiof_spi_priv *p)
1112 {
1113 	struct platform_device *pdev = p->pdev;
1114 	struct device *dev = &pdev->dev;
1115 	const struct sh_msiof_spi_info *info = dev_get_platdata(dev);
1116 	unsigned int dma_tx_id, dma_rx_id;
1117 	const struct resource *res;
1118 	struct spi_master *master;
1119 	struct device *tx_dev, *rx_dev;
1120 
1121 	if (dev->of_node) {
1122 		/* In the OF case we will get the slave IDs from the DT */
1123 		dma_tx_id = 0;
1124 		dma_rx_id = 0;
1125 	} else if (info && info->dma_tx_id && info->dma_rx_id) {
1126 		dma_tx_id = info->dma_tx_id;
1127 		dma_rx_id = info->dma_rx_id;
1128 	} else {
1129 		/* The driver assumes no error */
1130 		return 0;
1131 	}
1132 
1133 	/* The DMA engine uses the second register set, if present */
1134 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1135 	if (!res)
1136 		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1137 
1138 	master = p->master;
1139 	master->dma_tx = sh_msiof_request_dma_chan(dev, DMA_MEM_TO_DEV,
1140 						   dma_tx_id,
1141 						   res->start + TFDR);
1142 	if (!master->dma_tx)
1143 		return -ENODEV;
1144 
1145 	master->dma_rx = sh_msiof_request_dma_chan(dev, DMA_DEV_TO_MEM,
1146 						   dma_rx_id,
1147 						   res->start + RFDR);
1148 	if (!master->dma_rx)
1149 		goto free_tx_chan;
1150 
1151 	p->tx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
1152 	if (!p->tx_dma_page)
1153 		goto free_rx_chan;
1154 
1155 	p->rx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
1156 	if (!p->rx_dma_page)
1157 		goto free_tx_page;
1158 
1159 	tx_dev = master->dma_tx->device->dev;
1160 	p->tx_dma_addr = dma_map_single(tx_dev, p->tx_dma_page, PAGE_SIZE,
1161 					DMA_TO_DEVICE);
1162 	if (dma_mapping_error(tx_dev, p->tx_dma_addr))
1163 		goto free_rx_page;
1164 
1165 	rx_dev = master->dma_rx->device->dev;
1166 	p->rx_dma_addr = dma_map_single(rx_dev, p->rx_dma_page, PAGE_SIZE,
1167 					DMA_FROM_DEVICE);
1168 	if (dma_mapping_error(rx_dev, p->rx_dma_addr))
1169 		goto unmap_tx_page;
1170 
1171 	dev_info(dev, "DMA available");
1172 	return 0;
1173 
1174 unmap_tx_page:
1175 	dma_unmap_single(tx_dev, p->tx_dma_addr, PAGE_SIZE, DMA_TO_DEVICE);
1176 free_rx_page:
1177 	free_page((unsigned long)p->rx_dma_page);
1178 free_tx_page:
1179 	free_page((unsigned long)p->tx_dma_page);
1180 free_rx_chan:
1181 	dma_release_channel(master->dma_rx);
1182 free_tx_chan:
1183 	dma_release_channel(master->dma_tx);
1184 	master->dma_tx = NULL;
1185 	return -ENODEV;
1186 }
1187 
1188 static void sh_msiof_release_dma(struct sh_msiof_spi_priv *p)
1189 {
1190 	struct spi_master *master = p->master;
1191 	struct device *dev;
1192 
1193 	if (!master->dma_tx)
1194 		return;
1195 
1196 	dev = &p->pdev->dev;
1197 	dma_unmap_single(master->dma_rx->device->dev, p->rx_dma_addr,
1198 			 PAGE_SIZE, DMA_FROM_DEVICE);
1199 	dma_unmap_single(master->dma_tx->device->dev, p->tx_dma_addr,
1200 			 PAGE_SIZE, DMA_TO_DEVICE);
1201 	free_page((unsigned long)p->rx_dma_page);
1202 	free_page((unsigned long)p->tx_dma_page);
1203 	dma_release_channel(master->dma_rx);
1204 	dma_release_channel(master->dma_tx);
1205 }
1206 
1207 static int sh_msiof_spi_probe(struct platform_device *pdev)
1208 {
1209 	struct resource	*r;
1210 	struct spi_master *master;
1211 	const struct sh_msiof_chipdata *chipdata;
1212 	const struct of_device_id *of_id;
1213 	struct sh_msiof_spi_info *info;
1214 	struct sh_msiof_spi_priv *p;
1215 	int i;
1216 	int ret;
1217 
1218 	of_id = of_match_device(sh_msiof_match, &pdev->dev);
1219 	if (of_id) {
1220 		chipdata = of_id->data;
1221 		info = sh_msiof_spi_parse_dt(&pdev->dev);
1222 	} else {
1223 		chipdata = (const void *)pdev->id_entry->driver_data;
1224 		info = dev_get_platdata(&pdev->dev);
1225 	}
1226 
1227 	if (!info) {
1228 		dev_err(&pdev->dev, "failed to obtain device info\n");
1229 		return -ENXIO;
1230 	}
1231 
1232 	if (info->mode == MSIOF_SPI_SLAVE)
1233 		master = spi_alloc_slave(&pdev->dev,
1234 					 sizeof(struct sh_msiof_spi_priv));
1235 	else
1236 		master = spi_alloc_master(&pdev->dev,
1237 					  sizeof(struct sh_msiof_spi_priv));
1238 	if (master == NULL)
1239 		return -ENOMEM;
1240 
1241 	p = spi_master_get_devdata(master);
1242 
1243 	platform_set_drvdata(pdev, p);
1244 	p->master = master;
1245 	p->info = info;
1246 	p->min_div = chipdata->min_div;
1247 
1248 	init_completion(&p->done);
1249 
1250 	p->clk = devm_clk_get(&pdev->dev, NULL);
1251 	if (IS_ERR(p->clk)) {
1252 		dev_err(&pdev->dev, "cannot get clock\n");
1253 		ret = PTR_ERR(p->clk);
1254 		goto err1;
1255 	}
1256 
1257 	i = platform_get_irq(pdev, 0);
1258 	if (i < 0) {
1259 		dev_err(&pdev->dev, "cannot get platform IRQ\n");
1260 		ret = -ENOENT;
1261 		goto err1;
1262 	}
1263 
1264 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1265 	p->mapbase = devm_ioremap_resource(&pdev->dev, r);
1266 	if (IS_ERR(p->mapbase)) {
1267 		ret = PTR_ERR(p->mapbase);
1268 		goto err1;
1269 	}
1270 
1271 	ret = devm_request_irq(&pdev->dev, i, sh_msiof_spi_irq, 0,
1272 			       dev_name(&pdev->dev), p);
1273 	if (ret) {
1274 		dev_err(&pdev->dev, "unable to request irq\n");
1275 		goto err1;
1276 	}
1277 
1278 	p->pdev = pdev;
1279 	pm_runtime_enable(&pdev->dev);
1280 
1281 	/* Platform data may override FIFO sizes */
1282 	p->tx_fifo_size = chipdata->tx_fifo_size;
1283 	p->rx_fifo_size = chipdata->rx_fifo_size;
1284 	if (p->info->tx_fifo_override)
1285 		p->tx_fifo_size = p->info->tx_fifo_override;
1286 	if (p->info->rx_fifo_override)
1287 		p->rx_fifo_size = p->info->rx_fifo_override;
1288 
1289 	/* init master code */
1290 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1291 	master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
1292 	master->flags = chipdata->master_flags;
1293 	master->bus_num = pdev->id;
1294 	master->dev.of_node = pdev->dev.of_node;
1295 	master->num_chipselect = p->info->num_chipselect;
1296 	master->setup = sh_msiof_spi_setup;
1297 	master->prepare_message = sh_msiof_prepare_message;
1298 	master->slave_abort = sh_msiof_slave_abort;
1299 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32);
1300 	master->auto_runtime_pm = true;
1301 	master->transfer_one = sh_msiof_transfer_one;
1302 
1303 	ret = sh_msiof_request_dma(p);
1304 	if (ret < 0)
1305 		dev_warn(&pdev->dev, "DMA not available, using PIO\n");
1306 
1307 	ret = devm_spi_register_master(&pdev->dev, master);
1308 	if (ret < 0) {
1309 		dev_err(&pdev->dev, "spi_register_master error.\n");
1310 		goto err2;
1311 	}
1312 
1313 	return 0;
1314 
1315  err2:
1316 	sh_msiof_release_dma(p);
1317 	pm_runtime_disable(&pdev->dev);
1318  err1:
1319 	spi_master_put(master);
1320 	return ret;
1321 }
1322 
1323 static int sh_msiof_spi_remove(struct platform_device *pdev)
1324 {
1325 	struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
1326 
1327 	sh_msiof_release_dma(p);
1328 	pm_runtime_disable(&pdev->dev);
1329 	return 0;
1330 }
1331 
1332 static const struct platform_device_id spi_driver_ids[] = {
1333 	{ "spi_sh_msiof",	(kernel_ulong_t)&sh_data },
1334 	{},
1335 };
1336 MODULE_DEVICE_TABLE(platform, spi_driver_ids);
1337 
1338 static struct platform_driver sh_msiof_spi_drv = {
1339 	.probe		= sh_msiof_spi_probe,
1340 	.remove		= sh_msiof_spi_remove,
1341 	.id_table	= spi_driver_ids,
1342 	.driver		= {
1343 		.name		= "spi_sh_msiof",
1344 		.of_match_table = of_match_ptr(sh_msiof_match),
1345 	},
1346 };
1347 module_platform_driver(sh_msiof_spi_drv);
1348 
1349 MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
1350 MODULE_AUTHOR("Magnus Damm");
1351 MODULE_LICENSE("GPL v2");
1352 MODULE_ALIAS("platform:spi_sh_msiof");
1353