xref: /openbmc/linux/drivers/spi/spi-sh-msiof.c (revision 174cd4b1)
1 /*
2  * SuperH MSIOF SPI Master Interface
3  *
4  * Copyright (c) 2009 Magnus Damm
5  * Copyright (C) 2014 Glider bvba
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  */
12 
13 #include <linux/bitmap.h>
14 #include <linux/clk.h>
15 #include <linux/completion.h>
16 #include <linux/delay.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/dmaengine.h>
19 #include <linux/err.h>
20 #include <linux/gpio.h>
21 #include <linux/interrupt.h>
22 #include <linux/io.h>
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/of.h>
26 #include <linux/of_device.h>
27 #include <linux/platform_device.h>
28 #include <linux/pm_runtime.h>
29 #include <linux/sh_dma.h>
30 
31 #include <linux/spi/sh_msiof.h>
32 #include <linux/spi/spi.h>
33 
34 #include <asm/unaligned.h>
35 
36 
37 struct sh_msiof_chipdata {
38 	u16 tx_fifo_size;
39 	u16 rx_fifo_size;
40 	u16 master_flags;
41 };
42 
43 struct sh_msiof_spi_priv {
44 	struct spi_master *master;
45 	void __iomem *mapbase;
46 	struct clk *clk;
47 	struct platform_device *pdev;
48 	struct sh_msiof_spi_info *info;
49 	struct completion done;
50 	unsigned int tx_fifo_size;
51 	unsigned int rx_fifo_size;
52 	void *tx_dma_page;
53 	void *rx_dma_page;
54 	dma_addr_t tx_dma_addr;
55 	dma_addr_t rx_dma_addr;
56 };
57 
58 #define TMDR1	0x00	/* Transmit Mode Register 1 */
59 #define TMDR2	0x04	/* Transmit Mode Register 2 */
60 #define TMDR3	0x08	/* Transmit Mode Register 3 */
61 #define RMDR1	0x10	/* Receive Mode Register 1 */
62 #define RMDR2	0x14	/* Receive Mode Register 2 */
63 #define RMDR3	0x18	/* Receive Mode Register 3 */
64 #define TSCR	0x20	/* Transmit Clock Select Register */
65 #define RSCR	0x22	/* Receive Clock Select Register (SH, A1, APE6) */
66 #define CTR	0x28	/* Control Register */
67 #define FCTR	0x30	/* FIFO Control Register */
68 #define STR	0x40	/* Status Register */
69 #define IER	0x44	/* Interrupt Enable Register */
70 #define TDR1	0x48	/* Transmit Control Data Register 1 (SH, A1) */
71 #define TDR2	0x4c	/* Transmit Control Data Register 2 (SH, A1) */
72 #define TFDR	0x50	/* Transmit FIFO Data Register */
73 #define RDR1	0x58	/* Receive Control Data Register 1 (SH, A1) */
74 #define RDR2	0x5c	/* Receive Control Data Register 2 (SH, A1) */
75 #define RFDR	0x60	/* Receive FIFO Data Register */
76 
77 /* TMDR1 and RMDR1 */
78 #define MDR1_TRMD	 0x80000000 /* Transfer Mode (1 = Master mode) */
79 #define MDR1_SYNCMD_MASK 0x30000000 /* SYNC Mode */
80 #define MDR1_SYNCMD_SPI	 0x20000000 /*   Level mode/SPI */
81 #define MDR1_SYNCMD_LR	 0x30000000 /*   L/R mode */
82 #define MDR1_SYNCAC_SHIFT	 25 /* Sync Polarity (1 = Active-low) */
83 #define MDR1_BITLSB_SHIFT	 24 /* MSB/LSB First (1 = LSB first) */
84 #define MDR1_DTDL_SHIFT		 20 /* Data Pin Bit Delay for MSIOF_SYNC */
85 #define MDR1_SYNCDL_SHIFT	 16 /* Frame Sync Signal Timing Delay */
86 #define MDR1_FLD_MASK	 0x0000000c /* Frame Sync Signal Interval (0-3) */
87 #define MDR1_FLD_SHIFT		  2
88 #define MDR1_XXSTP	 0x00000001 /* Transmission/Reception Stop on FIFO */
89 /* TMDR1 */
90 #define TMDR1_PCON	 0x40000000 /* Transfer Signal Connection */
91 
92 /* TMDR2 and RMDR2 */
93 #define MDR2_BITLEN1(i)	(((i) - 1) << 24) /* Data Size (8-32 bits) */
94 #define MDR2_WDLEN1(i)	(((i) - 1) << 16) /* Word Count (1-64/256 (SH, A1))) */
95 #define MDR2_GRPMASK1	0x00000001 /* Group Output Mask 1 (SH, A1) */
96 
97 /* TSCR and RSCR */
98 #define SCR_BRPS_MASK	    0x1f00 /* Prescaler Setting (1-32) */
99 #define SCR_BRPS(i)	(((i) - 1) << 8)
100 #define SCR_BRDV_MASK	    0x0007 /* Baud Rate Generator's Division Ratio */
101 #define SCR_BRDV_DIV_2	    0x0000
102 #define SCR_BRDV_DIV_4	    0x0001
103 #define SCR_BRDV_DIV_8	    0x0002
104 #define SCR_BRDV_DIV_16	    0x0003
105 #define SCR_BRDV_DIV_32	    0x0004
106 #define SCR_BRDV_DIV_1	    0x0007
107 
108 /* CTR */
109 #define CTR_TSCKIZ_MASK	0xc0000000 /* Transmit Clock I/O Polarity Select */
110 #define CTR_TSCKIZ_SCK	0x80000000 /*   Disable SCK when TX disabled */
111 #define CTR_TSCKIZ_POL_SHIFT	30 /*   Transmit Clock Polarity */
112 #define CTR_RSCKIZ_MASK	0x30000000 /* Receive Clock Polarity Select */
113 #define CTR_RSCKIZ_SCK	0x20000000 /*   Must match CTR_TSCKIZ_SCK */
114 #define CTR_RSCKIZ_POL_SHIFT	28 /*   Receive Clock Polarity */
115 #define CTR_TEDG_SHIFT		27 /* Transmit Timing (1 = falling edge) */
116 #define CTR_REDG_SHIFT		26 /* Receive Timing (1 = falling edge) */
117 #define CTR_TXDIZ_MASK	0x00c00000 /* Pin Output When TX is Disabled */
118 #define CTR_TXDIZ_LOW	0x00000000 /*   0 */
119 #define CTR_TXDIZ_HIGH	0x00400000 /*   1 */
120 #define CTR_TXDIZ_HIZ	0x00800000 /*   High-impedance */
121 #define CTR_TSCKE	0x00008000 /* Transmit Serial Clock Output Enable */
122 #define CTR_TFSE	0x00004000 /* Transmit Frame Sync Signal Output Enable */
123 #define CTR_TXE		0x00000200 /* Transmit Enable */
124 #define CTR_RXE		0x00000100 /* Receive Enable */
125 
126 /* FCTR */
127 #define FCTR_TFWM_MASK	0xe0000000 /* Transmit FIFO Watermark */
128 #define FCTR_TFWM_64	0x00000000 /*  Transfer Request when 64 empty stages */
129 #define FCTR_TFWM_32	0x20000000 /*  Transfer Request when 32 empty stages */
130 #define FCTR_TFWM_24	0x40000000 /*  Transfer Request when 24 empty stages */
131 #define FCTR_TFWM_16	0x60000000 /*  Transfer Request when 16 empty stages */
132 #define FCTR_TFWM_12	0x80000000 /*  Transfer Request when 12 empty stages */
133 #define FCTR_TFWM_8	0xa0000000 /*  Transfer Request when 8 empty stages */
134 #define FCTR_TFWM_4	0xc0000000 /*  Transfer Request when 4 empty stages */
135 #define FCTR_TFWM_1	0xe0000000 /*  Transfer Request when 1 empty stage */
136 #define FCTR_TFUA_MASK	0x07f00000 /* Transmit FIFO Usable Area */
137 #define FCTR_TFUA_SHIFT		20
138 #define FCTR_TFUA(i)	((i) << FCTR_TFUA_SHIFT)
139 #define FCTR_RFWM_MASK	0x0000e000 /* Receive FIFO Watermark */
140 #define FCTR_RFWM_1	0x00000000 /*  Transfer Request when 1 valid stages */
141 #define FCTR_RFWM_4	0x00002000 /*  Transfer Request when 4 valid stages */
142 #define FCTR_RFWM_8	0x00004000 /*  Transfer Request when 8 valid stages */
143 #define FCTR_RFWM_16	0x00006000 /*  Transfer Request when 16 valid stages */
144 #define FCTR_RFWM_32	0x00008000 /*  Transfer Request when 32 valid stages */
145 #define FCTR_RFWM_64	0x0000a000 /*  Transfer Request when 64 valid stages */
146 #define FCTR_RFWM_128	0x0000c000 /*  Transfer Request when 128 valid stages */
147 #define FCTR_RFWM_256	0x0000e000 /*  Transfer Request when 256 valid stages */
148 #define FCTR_RFUA_MASK	0x00001ff0 /* Receive FIFO Usable Area (0x40 = full) */
149 #define FCTR_RFUA_SHIFT		 4
150 #define FCTR_RFUA(i)	((i) << FCTR_RFUA_SHIFT)
151 
152 /* STR */
153 #define STR_TFEMP	0x20000000 /* Transmit FIFO Empty */
154 #define STR_TDREQ	0x10000000 /* Transmit Data Transfer Request */
155 #define STR_TEOF	0x00800000 /* Frame Transmission End */
156 #define STR_TFSERR	0x00200000 /* Transmit Frame Synchronization Error */
157 #define STR_TFOVF	0x00100000 /* Transmit FIFO Overflow */
158 #define STR_TFUDF	0x00080000 /* Transmit FIFO Underflow */
159 #define STR_RFFUL	0x00002000 /* Receive FIFO Full */
160 #define STR_RDREQ	0x00001000 /* Receive Data Transfer Request */
161 #define STR_REOF	0x00000080 /* Frame Reception End */
162 #define STR_RFSERR	0x00000020 /* Receive Frame Synchronization Error */
163 #define STR_RFUDF	0x00000010 /* Receive FIFO Underflow */
164 #define STR_RFOVF	0x00000008 /* Receive FIFO Overflow */
165 
166 /* IER */
167 #define IER_TDMAE	0x80000000 /* Transmit Data DMA Transfer Req. Enable */
168 #define IER_TFEMPE	0x20000000 /* Transmit FIFO Empty Enable */
169 #define IER_TDREQE	0x10000000 /* Transmit Data Transfer Request Enable */
170 #define IER_TEOFE	0x00800000 /* Frame Transmission End Enable */
171 #define IER_TFSERRE	0x00200000 /* Transmit Frame Sync Error Enable */
172 #define IER_TFOVFE	0x00100000 /* Transmit FIFO Overflow Enable */
173 #define IER_TFUDFE	0x00080000 /* Transmit FIFO Underflow Enable */
174 #define IER_RDMAE	0x00008000 /* Receive Data DMA Transfer Req. Enable */
175 #define IER_RFFULE	0x00002000 /* Receive FIFO Full Enable */
176 #define IER_RDREQE	0x00001000 /* Receive Data Transfer Request Enable */
177 #define IER_REOFE	0x00000080 /* Frame Reception End Enable */
178 #define IER_RFSERRE	0x00000020 /* Receive Frame Sync Error Enable */
179 #define IER_RFUDFE	0x00000010 /* Receive FIFO Underflow Enable */
180 #define IER_RFOVFE	0x00000008 /* Receive FIFO Overflow Enable */
181 
182 
183 static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs)
184 {
185 	switch (reg_offs) {
186 	case TSCR:
187 	case RSCR:
188 		return ioread16(p->mapbase + reg_offs);
189 	default:
190 		return ioread32(p->mapbase + reg_offs);
191 	}
192 }
193 
194 static void sh_msiof_write(struct sh_msiof_spi_priv *p, int reg_offs,
195 			   u32 value)
196 {
197 	switch (reg_offs) {
198 	case TSCR:
199 	case RSCR:
200 		iowrite16(value, p->mapbase + reg_offs);
201 		break;
202 	default:
203 		iowrite32(value, p->mapbase + reg_offs);
204 		break;
205 	}
206 }
207 
208 static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv *p,
209 				    u32 clr, u32 set)
210 {
211 	u32 mask = clr | set;
212 	u32 data;
213 	int k;
214 
215 	data = sh_msiof_read(p, CTR);
216 	data &= ~clr;
217 	data |= set;
218 	sh_msiof_write(p, CTR, data);
219 
220 	for (k = 100; k > 0; k--) {
221 		if ((sh_msiof_read(p, CTR) & mask) == set)
222 			break;
223 
224 		udelay(10);
225 	}
226 
227 	return k > 0 ? 0 : -ETIMEDOUT;
228 }
229 
230 static irqreturn_t sh_msiof_spi_irq(int irq, void *data)
231 {
232 	struct sh_msiof_spi_priv *p = data;
233 
234 	/* just disable the interrupt and wake up */
235 	sh_msiof_write(p, IER, 0);
236 	complete(&p->done);
237 
238 	return IRQ_HANDLED;
239 }
240 
241 static struct {
242 	unsigned short div;
243 	unsigned short brdv;
244 } const sh_msiof_spi_div_table[] = {
245 	{ 1,	SCR_BRDV_DIV_1 },
246 	{ 2,	SCR_BRDV_DIV_2 },
247 	{ 4,	SCR_BRDV_DIV_4 },
248 	{ 8,	SCR_BRDV_DIV_8 },
249 	{ 16,	SCR_BRDV_DIV_16 },
250 	{ 32,	SCR_BRDV_DIV_32 },
251 };
252 
253 static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
254 				      unsigned long parent_rate, u32 spi_hz)
255 {
256 	unsigned long div = 1024;
257 	u32 brps, scr;
258 	size_t k;
259 
260 	if (!WARN_ON(!spi_hz || !parent_rate))
261 		div = DIV_ROUND_UP(parent_rate, spi_hz);
262 
263 	for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_div_table); k++) {
264 		brps = DIV_ROUND_UP(div, sh_msiof_spi_div_table[k].div);
265 		/* SCR_BRDV_DIV_1 is valid only if BRPS is x 1/1 or x 1/2 */
266 		if (sh_msiof_spi_div_table[k].div == 1 && brps > 2)
267 			continue;
268 		if (brps <= 32) /* max of brdv is 32 */
269 			break;
270 	}
271 
272 	k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_div_table) - 1);
273 
274 	scr = sh_msiof_spi_div_table[k].brdv | SCR_BRPS(brps);
275 	sh_msiof_write(p, TSCR, scr);
276 	if (!(p->master->flags & SPI_MASTER_MUST_TX))
277 		sh_msiof_write(p, RSCR, scr);
278 }
279 
280 static u32 sh_msiof_get_delay_bit(u32 dtdl_or_syncdl)
281 {
282 	/*
283 	 * DTDL/SYNCDL bit	: p->info->dtdl or p->info->syncdl
284 	 * b'000		: 0
285 	 * b'001		: 100
286 	 * b'010		: 200
287 	 * b'011 (SYNCDL only)	: 300
288 	 * b'101		: 50
289 	 * b'110		: 150
290 	 */
291 	if (dtdl_or_syncdl % 100)
292 		return dtdl_or_syncdl / 100 + 5;
293 	else
294 		return dtdl_or_syncdl / 100;
295 }
296 
297 static u32 sh_msiof_spi_get_dtdl_and_syncdl(struct sh_msiof_spi_priv *p)
298 {
299 	u32 val;
300 
301 	if (!p->info)
302 		return 0;
303 
304 	/* check if DTDL and SYNCDL is allowed value */
305 	if (p->info->dtdl > 200 || p->info->syncdl > 300) {
306 		dev_warn(&p->pdev->dev, "DTDL or SYNCDL is too large\n");
307 		return 0;
308 	}
309 
310 	/* check if the sum of DTDL and SYNCDL becomes an integer value  */
311 	if ((p->info->dtdl + p->info->syncdl) % 100) {
312 		dev_warn(&p->pdev->dev, "the sum of DTDL/SYNCDL is not good\n");
313 		return 0;
314 	}
315 
316 	val = sh_msiof_get_delay_bit(p->info->dtdl) << MDR1_DTDL_SHIFT;
317 	val |= sh_msiof_get_delay_bit(p->info->syncdl) << MDR1_SYNCDL_SHIFT;
318 
319 	return val;
320 }
321 
322 static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
323 				      u32 cpol, u32 cpha,
324 				      u32 tx_hi_z, u32 lsb_first, u32 cs_high)
325 {
326 	u32 tmp;
327 	int edge;
328 
329 	/*
330 	 * CPOL CPHA     TSCKIZ RSCKIZ TEDG REDG
331 	 *    0    0         10     10    1    1
332 	 *    0    1         10     10    0    0
333 	 *    1    0         11     11    0    0
334 	 *    1    1         11     11    1    1
335 	 */
336 	tmp = MDR1_SYNCMD_SPI | 1 << MDR1_FLD_SHIFT | MDR1_XXSTP;
337 	tmp |= !cs_high << MDR1_SYNCAC_SHIFT;
338 	tmp |= lsb_first << MDR1_BITLSB_SHIFT;
339 	tmp |= sh_msiof_spi_get_dtdl_and_syncdl(p);
340 	sh_msiof_write(p, TMDR1, tmp | MDR1_TRMD | TMDR1_PCON);
341 	if (p->master->flags & SPI_MASTER_MUST_TX) {
342 		/* These bits are reserved if RX needs TX */
343 		tmp &= ~0x0000ffff;
344 	}
345 	sh_msiof_write(p, RMDR1, tmp);
346 
347 	tmp = 0;
348 	tmp |= CTR_TSCKIZ_SCK | cpol << CTR_TSCKIZ_POL_SHIFT;
349 	tmp |= CTR_RSCKIZ_SCK | cpol << CTR_RSCKIZ_POL_SHIFT;
350 
351 	edge = cpol ^ !cpha;
352 
353 	tmp |= edge << CTR_TEDG_SHIFT;
354 	tmp |= edge << CTR_REDG_SHIFT;
355 	tmp |= tx_hi_z ? CTR_TXDIZ_HIZ : CTR_TXDIZ_LOW;
356 	sh_msiof_write(p, CTR, tmp);
357 }
358 
359 static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
360 				       const void *tx_buf, void *rx_buf,
361 				       u32 bits, u32 words)
362 {
363 	u32 dr2 = MDR2_BITLEN1(bits) | MDR2_WDLEN1(words);
364 
365 	if (tx_buf || (p->master->flags & SPI_MASTER_MUST_TX))
366 		sh_msiof_write(p, TMDR2, dr2);
367 	else
368 		sh_msiof_write(p, TMDR2, dr2 | MDR2_GRPMASK1);
369 
370 	if (rx_buf)
371 		sh_msiof_write(p, RMDR2, dr2);
372 }
373 
374 static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
375 {
376 	sh_msiof_write(p, STR, sh_msiof_read(p, STR));
377 }
378 
379 static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
380 				      const void *tx_buf, int words, int fs)
381 {
382 	const u8 *buf_8 = tx_buf;
383 	int k;
384 
385 	for (k = 0; k < words; k++)
386 		sh_msiof_write(p, TFDR, buf_8[k] << fs);
387 }
388 
389 static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
390 				       const void *tx_buf, int words, int fs)
391 {
392 	const u16 *buf_16 = tx_buf;
393 	int k;
394 
395 	for (k = 0; k < words; k++)
396 		sh_msiof_write(p, TFDR, buf_16[k] << fs);
397 }
398 
399 static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
400 					const void *tx_buf, int words, int fs)
401 {
402 	const u16 *buf_16 = tx_buf;
403 	int k;
404 
405 	for (k = 0; k < words; k++)
406 		sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
407 }
408 
409 static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
410 				       const void *tx_buf, int words, int fs)
411 {
412 	const u32 *buf_32 = tx_buf;
413 	int k;
414 
415 	for (k = 0; k < words; k++)
416 		sh_msiof_write(p, TFDR, buf_32[k] << fs);
417 }
418 
419 static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
420 					const void *tx_buf, int words, int fs)
421 {
422 	const u32 *buf_32 = tx_buf;
423 	int k;
424 
425 	for (k = 0; k < words; k++)
426 		sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
427 }
428 
429 static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
430 					const void *tx_buf, int words, int fs)
431 {
432 	const u32 *buf_32 = tx_buf;
433 	int k;
434 
435 	for (k = 0; k < words; k++)
436 		sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
437 }
438 
439 static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
440 					 const void *tx_buf, int words, int fs)
441 {
442 	const u32 *buf_32 = tx_buf;
443 	int k;
444 
445 	for (k = 0; k < words; k++)
446 		sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
447 }
448 
449 static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
450 				     void *rx_buf, int words, int fs)
451 {
452 	u8 *buf_8 = rx_buf;
453 	int k;
454 
455 	for (k = 0; k < words; k++)
456 		buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
457 }
458 
459 static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
460 				      void *rx_buf, int words, int fs)
461 {
462 	u16 *buf_16 = rx_buf;
463 	int k;
464 
465 	for (k = 0; k < words; k++)
466 		buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
467 }
468 
469 static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
470 				       void *rx_buf, int words, int fs)
471 {
472 	u16 *buf_16 = rx_buf;
473 	int k;
474 
475 	for (k = 0; k < words; k++)
476 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
477 }
478 
479 static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
480 				      void *rx_buf, int words, int fs)
481 {
482 	u32 *buf_32 = rx_buf;
483 	int k;
484 
485 	for (k = 0; k < words; k++)
486 		buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
487 }
488 
489 static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
490 				       void *rx_buf, int words, int fs)
491 {
492 	u32 *buf_32 = rx_buf;
493 	int k;
494 
495 	for (k = 0; k < words; k++)
496 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
497 }
498 
499 static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
500 				       void *rx_buf, int words, int fs)
501 {
502 	u32 *buf_32 = rx_buf;
503 	int k;
504 
505 	for (k = 0; k < words; k++)
506 		buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
507 }
508 
509 static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
510 				       void *rx_buf, int words, int fs)
511 {
512 	u32 *buf_32 = rx_buf;
513 	int k;
514 
515 	for (k = 0; k < words; k++)
516 		put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
517 }
518 
519 static int sh_msiof_spi_setup(struct spi_device *spi)
520 {
521 	struct device_node	*np = spi->master->dev.of_node;
522 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
523 
524 	pm_runtime_get_sync(&p->pdev->dev);
525 
526 	if (!np) {
527 		/*
528 		 * Use spi->controller_data for CS (same strategy as spi_gpio),
529 		 * if any. otherwise let HW control CS
530 		 */
531 		spi->cs_gpio = (uintptr_t)spi->controller_data;
532 	}
533 
534 	/* Configure pins before deasserting CS */
535 	sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
536 				  !!(spi->mode & SPI_CPHA),
537 				  !!(spi->mode & SPI_3WIRE),
538 				  !!(spi->mode & SPI_LSB_FIRST),
539 				  !!(spi->mode & SPI_CS_HIGH));
540 
541 	if (spi->cs_gpio >= 0)
542 		gpio_set_value(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
543 
544 
545 	pm_runtime_put(&p->pdev->dev);
546 
547 	return 0;
548 }
549 
550 static int sh_msiof_prepare_message(struct spi_master *master,
551 				    struct spi_message *msg)
552 {
553 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
554 	const struct spi_device *spi = msg->spi;
555 
556 	/* Configure pins before asserting CS */
557 	sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
558 				  !!(spi->mode & SPI_CPHA),
559 				  !!(spi->mode & SPI_3WIRE),
560 				  !!(spi->mode & SPI_LSB_FIRST),
561 				  !!(spi->mode & SPI_CS_HIGH));
562 	return 0;
563 }
564 
565 static int sh_msiof_spi_start(struct sh_msiof_spi_priv *p, void *rx_buf)
566 {
567 	int ret;
568 
569 	/* setup clock and rx/tx signals */
570 	ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
571 	if (rx_buf && !ret)
572 		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
573 	if (!ret)
574 		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);
575 
576 	/* start by setting frame bit */
577 	if (!ret)
578 		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
579 
580 	return ret;
581 }
582 
583 static int sh_msiof_spi_stop(struct sh_msiof_spi_priv *p, void *rx_buf)
584 {
585 	int ret;
586 
587 	/* shut down frame, rx/tx and clock signals */
588 	ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
589 	if (!ret)
590 		ret = sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
591 	if (rx_buf && !ret)
592 		ret = sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
593 	if (!ret)
594 		ret = sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
595 
596 	return ret;
597 }
598 
599 static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
600 				  void (*tx_fifo)(struct sh_msiof_spi_priv *,
601 						  const void *, int, int),
602 				  void (*rx_fifo)(struct sh_msiof_spi_priv *,
603 						  void *, int, int),
604 				  const void *tx_buf, void *rx_buf,
605 				  int words, int bits)
606 {
607 	int fifo_shift;
608 	int ret;
609 
610 	/* limit maximum word transfer to rx/tx fifo size */
611 	if (tx_buf)
612 		words = min_t(int, words, p->tx_fifo_size);
613 	if (rx_buf)
614 		words = min_t(int, words, p->rx_fifo_size);
615 
616 	/* the fifo contents need shifting */
617 	fifo_shift = 32 - bits;
618 
619 	/* default FIFO watermarks for PIO */
620 	sh_msiof_write(p, FCTR, 0);
621 
622 	/* setup msiof transfer mode registers */
623 	sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);
624 	sh_msiof_write(p, IER, IER_TEOFE | IER_REOFE);
625 
626 	/* write tx fifo */
627 	if (tx_buf)
628 		tx_fifo(p, tx_buf, words, fifo_shift);
629 
630 	reinit_completion(&p->done);
631 
632 	ret = sh_msiof_spi_start(p, rx_buf);
633 	if (ret) {
634 		dev_err(&p->pdev->dev, "failed to start hardware\n");
635 		goto stop_ier;
636 	}
637 
638 	/* wait for tx fifo to be emptied / rx fifo to be filled */
639 	if (!wait_for_completion_timeout(&p->done, HZ)) {
640 		dev_err(&p->pdev->dev, "PIO timeout\n");
641 		ret = -ETIMEDOUT;
642 		goto stop_reset;
643 	}
644 
645 	/* read rx fifo */
646 	if (rx_buf)
647 		rx_fifo(p, rx_buf, words, fifo_shift);
648 
649 	/* clear status bits */
650 	sh_msiof_reset_str(p);
651 
652 	ret = sh_msiof_spi_stop(p, rx_buf);
653 	if (ret) {
654 		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
655 		return ret;
656 	}
657 
658 	return words;
659 
660 stop_reset:
661 	sh_msiof_reset_str(p);
662 	sh_msiof_spi_stop(p, rx_buf);
663 stop_ier:
664 	sh_msiof_write(p, IER, 0);
665 	return ret;
666 }
667 
668 static void sh_msiof_dma_complete(void *arg)
669 {
670 	struct sh_msiof_spi_priv *p = arg;
671 
672 	sh_msiof_write(p, IER, 0);
673 	complete(&p->done);
674 }
675 
676 static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
677 			     void *rx, unsigned int len)
678 {
679 	u32 ier_bits = 0;
680 	struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
681 	dma_cookie_t cookie;
682 	int ret;
683 
684 	/* First prepare and submit the DMA request(s), as this may fail */
685 	if (rx) {
686 		ier_bits |= IER_RDREQE | IER_RDMAE;
687 		desc_rx = dmaengine_prep_slave_single(p->master->dma_rx,
688 					p->rx_dma_addr, len, DMA_FROM_DEVICE,
689 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
690 		if (!desc_rx)
691 			return -EAGAIN;
692 
693 		desc_rx->callback = sh_msiof_dma_complete;
694 		desc_rx->callback_param = p;
695 		cookie = dmaengine_submit(desc_rx);
696 		if (dma_submit_error(cookie))
697 			return cookie;
698 	}
699 
700 	if (tx) {
701 		ier_bits |= IER_TDREQE | IER_TDMAE;
702 		dma_sync_single_for_device(p->master->dma_tx->device->dev,
703 					   p->tx_dma_addr, len, DMA_TO_DEVICE);
704 		desc_tx = dmaengine_prep_slave_single(p->master->dma_tx,
705 					p->tx_dma_addr, len, DMA_TO_DEVICE,
706 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
707 		if (!desc_tx) {
708 			ret = -EAGAIN;
709 			goto no_dma_tx;
710 		}
711 
712 		if (rx) {
713 			/* No callback */
714 			desc_tx->callback = NULL;
715 		} else {
716 			desc_tx->callback = sh_msiof_dma_complete;
717 			desc_tx->callback_param = p;
718 		}
719 		cookie = dmaengine_submit(desc_tx);
720 		if (dma_submit_error(cookie)) {
721 			ret = cookie;
722 			goto no_dma_tx;
723 		}
724 	}
725 
726 	/* 1 stage FIFO watermarks for DMA */
727 	sh_msiof_write(p, FCTR, FCTR_TFWM_1 | FCTR_RFWM_1);
728 
729 	/* setup msiof transfer mode registers (32-bit words) */
730 	sh_msiof_spi_set_mode_regs(p, tx, rx, 32, len / 4);
731 
732 	sh_msiof_write(p, IER, ier_bits);
733 
734 	reinit_completion(&p->done);
735 
736 	/* Now start DMA */
737 	if (rx)
738 		dma_async_issue_pending(p->master->dma_rx);
739 	if (tx)
740 		dma_async_issue_pending(p->master->dma_tx);
741 
742 	ret = sh_msiof_spi_start(p, rx);
743 	if (ret) {
744 		dev_err(&p->pdev->dev, "failed to start hardware\n");
745 		goto stop_dma;
746 	}
747 
748 	/* wait for tx fifo to be emptied / rx fifo to be filled */
749 	if (!wait_for_completion_timeout(&p->done, HZ)) {
750 		dev_err(&p->pdev->dev, "DMA timeout\n");
751 		ret = -ETIMEDOUT;
752 		goto stop_reset;
753 	}
754 
755 	/* clear status bits */
756 	sh_msiof_reset_str(p);
757 
758 	ret = sh_msiof_spi_stop(p, rx);
759 	if (ret) {
760 		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
761 		return ret;
762 	}
763 
764 	if (rx)
765 		dma_sync_single_for_cpu(p->master->dma_rx->device->dev,
766 					p->rx_dma_addr, len,
767 					DMA_FROM_DEVICE);
768 
769 	return 0;
770 
771 stop_reset:
772 	sh_msiof_reset_str(p);
773 	sh_msiof_spi_stop(p, rx);
774 stop_dma:
775 	if (tx)
776 		dmaengine_terminate_all(p->master->dma_tx);
777 no_dma_tx:
778 	if (rx)
779 		dmaengine_terminate_all(p->master->dma_rx);
780 	sh_msiof_write(p, IER, 0);
781 	return ret;
782 }
783 
784 static void copy_bswap32(u32 *dst, const u32 *src, unsigned int words)
785 {
786 	/* src or dst can be unaligned, but not both */
787 	if ((unsigned long)src & 3) {
788 		while (words--) {
789 			*dst++ = swab32(get_unaligned(src));
790 			src++;
791 		}
792 	} else if ((unsigned long)dst & 3) {
793 		while (words--) {
794 			put_unaligned(swab32(*src++), dst);
795 			dst++;
796 		}
797 	} else {
798 		while (words--)
799 			*dst++ = swab32(*src++);
800 	}
801 }
802 
803 static void copy_wswap32(u32 *dst, const u32 *src, unsigned int words)
804 {
805 	/* src or dst can be unaligned, but not both */
806 	if ((unsigned long)src & 3) {
807 		while (words--) {
808 			*dst++ = swahw32(get_unaligned(src));
809 			src++;
810 		}
811 	} else if ((unsigned long)dst & 3) {
812 		while (words--) {
813 			put_unaligned(swahw32(*src++), dst);
814 			dst++;
815 		}
816 	} else {
817 		while (words--)
818 			*dst++ = swahw32(*src++);
819 	}
820 }
821 
822 static void copy_plain32(u32 *dst, const u32 *src, unsigned int words)
823 {
824 	memcpy(dst, src, words * 4);
825 }
826 
827 static int sh_msiof_transfer_one(struct spi_master *master,
828 				 struct spi_device *spi,
829 				 struct spi_transfer *t)
830 {
831 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
832 	void (*copy32)(u32 *, const u32 *, unsigned int);
833 	void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
834 	void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
835 	const void *tx_buf = t->tx_buf;
836 	void *rx_buf = t->rx_buf;
837 	unsigned int len = t->len;
838 	unsigned int bits = t->bits_per_word;
839 	unsigned int bytes_per_word;
840 	unsigned int words;
841 	int n;
842 	bool swab;
843 	int ret;
844 
845 	/* setup clocks (clock already enabled in chipselect()) */
846 	sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk), t->speed_hz);
847 
848 	while (master->dma_tx && len > 15) {
849 		/*
850 		 *  DMA supports 32-bit words only, hence pack 8-bit and 16-bit
851 		 *  words, with byte resp. word swapping.
852 		 */
853 		unsigned int l = 0;
854 
855 		if (tx_buf)
856 			l = min(len, p->tx_fifo_size * 4);
857 		if (rx_buf)
858 			l = min(len, p->rx_fifo_size * 4);
859 
860 		if (bits <= 8) {
861 			if (l & 3)
862 				break;
863 			copy32 = copy_bswap32;
864 		} else if (bits <= 16) {
865 			if (l & 1)
866 				break;
867 			copy32 = copy_wswap32;
868 		} else {
869 			copy32 = copy_plain32;
870 		}
871 
872 		if (tx_buf)
873 			copy32(p->tx_dma_page, tx_buf, l / 4);
874 
875 		ret = sh_msiof_dma_once(p, tx_buf, rx_buf, l);
876 		if (ret == -EAGAIN) {
877 			pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
878 				     dev_driver_string(&p->pdev->dev),
879 				     dev_name(&p->pdev->dev));
880 			break;
881 		}
882 		if (ret)
883 			return ret;
884 
885 		if (rx_buf) {
886 			copy32(rx_buf, p->rx_dma_page, l / 4);
887 			rx_buf += l;
888 		}
889 		if (tx_buf)
890 			tx_buf += l;
891 
892 		len -= l;
893 		if (!len)
894 			return 0;
895 	}
896 
897 	if (bits <= 8 && len > 15 && !(len & 3)) {
898 		bits = 32;
899 		swab = true;
900 	} else {
901 		swab = false;
902 	}
903 
904 	/* setup bytes per word and fifo read/write functions */
905 	if (bits <= 8) {
906 		bytes_per_word = 1;
907 		tx_fifo = sh_msiof_spi_write_fifo_8;
908 		rx_fifo = sh_msiof_spi_read_fifo_8;
909 	} else if (bits <= 16) {
910 		bytes_per_word = 2;
911 		if ((unsigned long)tx_buf & 0x01)
912 			tx_fifo = sh_msiof_spi_write_fifo_16u;
913 		else
914 			tx_fifo = sh_msiof_spi_write_fifo_16;
915 
916 		if ((unsigned long)rx_buf & 0x01)
917 			rx_fifo = sh_msiof_spi_read_fifo_16u;
918 		else
919 			rx_fifo = sh_msiof_spi_read_fifo_16;
920 	} else if (swab) {
921 		bytes_per_word = 4;
922 		if ((unsigned long)tx_buf & 0x03)
923 			tx_fifo = sh_msiof_spi_write_fifo_s32u;
924 		else
925 			tx_fifo = sh_msiof_spi_write_fifo_s32;
926 
927 		if ((unsigned long)rx_buf & 0x03)
928 			rx_fifo = sh_msiof_spi_read_fifo_s32u;
929 		else
930 			rx_fifo = sh_msiof_spi_read_fifo_s32;
931 	} else {
932 		bytes_per_word = 4;
933 		if ((unsigned long)tx_buf & 0x03)
934 			tx_fifo = sh_msiof_spi_write_fifo_32u;
935 		else
936 			tx_fifo = sh_msiof_spi_write_fifo_32;
937 
938 		if ((unsigned long)rx_buf & 0x03)
939 			rx_fifo = sh_msiof_spi_read_fifo_32u;
940 		else
941 			rx_fifo = sh_msiof_spi_read_fifo_32;
942 	}
943 
944 	/* transfer in fifo sized chunks */
945 	words = len / bytes_per_word;
946 
947 	while (words > 0) {
948 		n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo, tx_buf, rx_buf,
949 					   words, bits);
950 		if (n < 0)
951 			return n;
952 
953 		if (tx_buf)
954 			tx_buf += n * bytes_per_word;
955 		if (rx_buf)
956 			rx_buf += n * bytes_per_word;
957 		words -= n;
958 	}
959 
960 	return 0;
961 }
962 
963 static const struct sh_msiof_chipdata sh_data = {
964 	.tx_fifo_size = 64,
965 	.rx_fifo_size = 64,
966 	.master_flags = 0,
967 };
968 
969 static const struct sh_msiof_chipdata r8a779x_data = {
970 	.tx_fifo_size = 64,
971 	.rx_fifo_size = 64,
972 	.master_flags = SPI_MASTER_MUST_TX,
973 };
974 
975 static const struct of_device_id sh_msiof_match[] = {
976 	{ .compatible = "renesas,sh-mobile-msiof", .data = &sh_data },
977 	{ .compatible = "renesas,msiof-r8a7790",   .data = &r8a779x_data },
978 	{ .compatible = "renesas,msiof-r8a7791",   .data = &r8a779x_data },
979 	{ .compatible = "renesas,msiof-r8a7792",   .data = &r8a779x_data },
980 	{ .compatible = "renesas,msiof-r8a7793",   .data = &r8a779x_data },
981 	{ .compatible = "renesas,msiof-r8a7794",   .data = &r8a779x_data },
982 	{ .compatible = "renesas,rcar-gen2-msiof", .data = &r8a779x_data },
983 	{ .compatible = "renesas,msiof-r8a7796",   .data = &r8a779x_data },
984 	{ .compatible = "renesas,rcar-gen3-msiof", .data = &r8a779x_data },
985 	{ .compatible = "renesas,sh-msiof",        .data = &sh_data }, /* Deprecated */
986 	{},
987 };
988 MODULE_DEVICE_TABLE(of, sh_msiof_match);
989 
990 #ifdef CONFIG_OF
991 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
992 {
993 	struct sh_msiof_spi_info *info;
994 	struct device_node *np = dev->of_node;
995 	u32 num_cs = 1;
996 
997 	info = devm_kzalloc(dev, sizeof(struct sh_msiof_spi_info), GFP_KERNEL);
998 	if (!info)
999 		return NULL;
1000 
1001 	/* Parse the MSIOF properties */
1002 	of_property_read_u32(np, "num-cs", &num_cs);
1003 	of_property_read_u32(np, "renesas,tx-fifo-size",
1004 					&info->tx_fifo_override);
1005 	of_property_read_u32(np, "renesas,rx-fifo-size",
1006 					&info->rx_fifo_override);
1007 	of_property_read_u32(np, "renesas,dtdl", &info->dtdl);
1008 	of_property_read_u32(np, "renesas,syncdl", &info->syncdl);
1009 
1010 	info->num_chipselect = num_cs;
1011 
1012 	return info;
1013 }
1014 #else
1015 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
1016 {
1017 	return NULL;
1018 }
1019 #endif
1020 
1021 static struct dma_chan *sh_msiof_request_dma_chan(struct device *dev,
1022 	enum dma_transfer_direction dir, unsigned int id, dma_addr_t port_addr)
1023 {
1024 	dma_cap_mask_t mask;
1025 	struct dma_chan *chan;
1026 	struct dma_slave_config cfg;
1027 	int ret;
1028 
1029 	dma_cap_zero(mask);
1030 	dma_cap_set(DMA_SLAVE, mask);
1031 
1032 	chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
1033 				(void *)(unsigned long)id, dev,
1034 				dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1035 	if (!chan) {
1036 		dev_warn(dev, "dma_request_slave_channel_compat failed\n");
1037 		return NULL;
1038 	}
1039 
1040 	memset(&cfg, 0, sizeof(cfg));
1041 	cfg.direction = dir;
1042 	if (dir == DMA_MEM_TO_DEV) {
1043 		cfg.dst_addr = port_addr;
1044 		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1045 	} else {
1046 		cfg.src_addr = port_addr;
1047 		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1048 	}
1049 
1050 	ret = dmaengine_slave_config(chan, &cfg);
1051 	if (ret) {
1052 		dev_warn(dev, "dmaengine_slave_config failed %d\n", ret);
1053 		dma_release_channel(chan);
1054 		return NULL;
1055 	}
1056 
1057 	return chan;
1058 }
1059 
1060 static int sh_msiof_request_dma(struct sh_msiof_spi_priv *p)
1061 {
1062 	struct platform_device *pdev = p->pdev;
1063 	struct device *dev = &pdev->dev;
1064 	const struct sh_msiof_spi_info *info = dev_get_platdata(dev);
1065 	unsigned int dma_tx_id, dma_rx_id;
1066 	const struct resource *res;
1067 	struct spi_master *master;
1068 	struct device *tx_dev, *rx_dev;
1069 
1070 	if (dev->of_node) {
1071 		/* In the OF case we will get the slave IDs from the DT */
1072 		dma_tx_id = 0;
1073 		dma_rx_id = 0;
1074 	} else if (info && info->dma_tx_id && info->dma_rx_id) {
1075 		dma_tx_id = info->dma_tx_id;
1076 		dma_rx_id = info->dma_rx_id;
1077 	} else {
1078 		/* The driver assumes no error */
1079 		return 0;
1080 	}
1081 
1082 	/* The DMA engine uses the second register set, if present */
1083 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1084 	if (!res)
1085 		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1086 
1087 	master = p->master;
1088 	master->dma_tx = sh_msiof_request_dma_chan(dev, DMA_MEM_TO_DEV,
1089 						   dma_tx_id,
1090 						   res->start + TFDR);
1091 	if (!master->dma_tx)
1092 		return -ENODEV;
1093 
1094 	master->dma_rx = sh_msiof_request_dma_chan(dev, DMA_DEV_TO_MEM,
1095 						   dma_rx_id,
1096 						   res->start + RFDR);
1097 	if (!master->dma_rx)
1098 		goto free_tx_chan;
1099 
1100 	p->tx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
1101 	if (!p->tx_dma_page)
1102 		goto free_rx_chan;
1103 
1104 	p->rx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
1105 	if (!p->rx_dma_page)
1106 		goto free_tx_page;
1107 
1108 	tx_dev = master->dma_tx->device->dev;
1109 	p->tx_dma_addr = dma_map_single(tx_dev, p->tx_dma_page, PAGE_SIZE,
1110 					DMA_TO_DEVICE);
1111 	if (dma_mapping_error(tx_dev, p->tx_dma_addr))
1112 		goto free_rx_page;
1113 
1114 	rx_dev = master->dma_rx->device->dev;
1115 	p->rx_dma_addr = dma_map_single(rx_dev, p->rx_dma_page, PAGE_SIZE,
1116 					DMA_FROM_DEVICE);
1117 	if (dma_mapping_error(rx_dev, p->rx_dma_addr))
1118 		goto unmap_tx_page;
1119 
1120 	dev_info(dev, "DMA available");
1121 	return 0;
1122 
1123 unmap_tx_page:
1124 	dma_unmap_single(tx_dev, p->tx_dma_addr, PAGE_SIZE, DMA_TO_DEVICE);
1125 free_rx_page:
1126 	free_page((unsigned long)p->rx_dma_page);
1127 free_tx_page:
1128 	free_page((unsigned long)p->tx_dma_page);
1129 free_rx_chan:
1130 	dma_release_channel(master->dma_rx);
1131 free_tx_chan:
1132 	dma_release_channel(master->dma_tx);
1133 	master->dma_tx = NULL;
1134 	return -ENODEV;
1135 }
1136 
1137 static void sh_msiof_release_dma(struct sh_msiof_spi_priv *p)
1138 {
1139 	struct spi_master *master = p->master;
1140 	struct device *dev;
1141 
1142 	if (!master->dma_tx)
1143 		return;
1144 
1145 	dev = &p->pdev->dev;
1146 	dma_unmap_single(master->dma_rx->device->dev, p->rx_dma_addr,
1147 			 PAGE_SIZE, DMA_FROM_DEVICE);
1148 	dma_unmap_single(master->dma_tx->device->dev, p->tx_dma_addr,
1149 			 PAGE_SIZE, DMA_TO_DEVICE);
1150 	free_page((unsigned long)p->rx_dma_page);
1151 	free_page((unsigned long)p->tx_dma_page);
1152 	dma_release_channel(master->dma_rx);
1153 	dma_release_channel(master->dma_tx);
1154 }
1155 
1156 static int sh_msiof_spi_probe(struct platform_device *pdev)
1157 {
1158 	struct resource	*r;
1159 	struct spi_master *master;
1160 	const struct sh_msiof_chipdata *chipdata;
1161 	const struct of_device_id *of_id;
1162 	struct sh_msiof_spi_priv *p;
1163 	int i;
1164 	int ret;
1165 
1166 	master = spi_alloc_master(&pdev->dev, sizeof(struct sh_msiof_spi_priv));
1167 	if (master == NULL)
1168 		return -ENOMEM;
1169 
1170 	p = spi_master_get_devdata(master);
1171 
1172 	platform_set_drvdata(pdev, p);
1173 	p->master = master;
1174 
1175 	of_id = of_match_device(sh_msiof_match, &pdev->dev);
1176 	if (of_id) {
1177 		chipdata = of_id->data;
1178 		p->info = sh_msiof_spi_parse_dt(&pdev->dev);
1179 	} else {
1180 		chipdata = (const void *)pdev->id_entry->driver_data;
1181 		p->info = dev_get_platdata(&pdev->dev);
1182 	}
1183 
1184 	if (!p->info) {
1185 		dev_err(&pdev->dev, "failed to obtain device info\n");
1186 		ret = -ENXIO;
1187 		goto err1;
1188 	}
1189 
1190 	init_completion(&p->done);
1191 
1192 	p->clk = devm_clk_get(&pdev->dev, NULL);
1193 	if (IS_ERR(p->clk)) {
1194 		dev_err(&pdev->dev, "cannot get clock\n");
1195 		ret = PTR_ERR(p->clk);
1196 		goto err1;
1197 	}
1198 
1199 	i = platform_get_irq(pdev, 0);
1200 	if (i < 0) {
1201 		dev_err(&pdev->dev, "cannot get platform IRQ\n");
1202 		ret = -ENOENT;
1203 		goto err1;
1204 	}
1205 
1206 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1207 	p->mapbase = devm_ioremap_resource(&pdev->dev, r);
1208 	if (IS_ERR(p->mapbase)) {
1209 		ret = PTR_ERR(p->mapbase);
1210 		goto err1;
1211 	}
1212 
1213 	ret = devm_request_irq(&pdev->dev, i, sh_msiof_spi_irq, 0,
1214 			       dev_name(&pdev->dev), p);
1215 	if (ret) {
1216 		dev_err(&pdev->dev, "unable to request irq\n");
1217 		goto err1;
1218 	}
1219 
1220 	p->pdev = pdev;
1221 	pm_runtime_enable(&pdev->dev);
1222 
1223 	/* Platform data may override FIFO sizes */
1224 	p->tx_fifo_size = chipdata->tx_fifo_size;
1225 	p->rx_fifo_size = chipdata->rx_fifo_size;
1226 	if (p->info->tx_fifo_override)
1227 		p->tx_fifo_size = p->info->tx_fifo_override;
1228 	if (p->info->rx_fifo_override)
1229 		p->rx_fifo_size = p->info->rx_fifo_override;
1230 
1231 	/* init master code */
1232 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1233 	master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
1234 	master->flags = chipdata->master_flags;
1235 	master->bus_num = pdev->id;
1236 	master->dev.of_node = pdev->dev.of_node;
1237 	master->num_chipselect = p->info->num_chipselect;
1238 	master->setup = sh_msiof_spi_setup;
1239 	master->prepare_message = sh_msiof_prepare_message;
1240 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32);
1241 	master->auto_runtime_pm = true;
1242 	master->transfer_one = sh_msiof_transfer_one;
1243 
1244 	ret = sh_msiof_request_dma(p);
1245 	if (ret < 0)
1246 		dev_warn(&pdev->dev, "DMA not available, using PIO\n");
1247 
1248 	ret = devm_spi_register_master(&pdev->dev, master);
1249 	if (ret < 0) {
1250 		dev_err(&pdev->dev, "spi_register_master error.\n");
1251 		goto err2;
1252 	}
1253 
1254 	return 0;
1255 
1256  err2:
1257 	sh_msiof_release_dma(p);
1258 	pm_runtime_disable(&pdev->dev);
1259  err1:
1260 	spi_master_put(master);
1261 	return ret;
1262 }
1263 
1264 static int sh_msiof_spi_remove(struct platform_device *pdev)
1265 {
1266 	struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
1267 
1268 	sh_msiof_release_dma(p);
1269 	pm_runtime_disable(&pdev->dev);
1270 	return 0;
1271 }
1272 
1273 static const struct platform_device_id spi_driver_ids[] = {
1274 	{ "spi_sh_msiof",	(kernel_ulong_t)&sh_data },
1275 	{},
1276 };
1277 MODULE_DEVICE_TABLE(platform, spi_driver_ids);
1278 
1279 static struct platform_driver sh_msiof_spi_drv = {
1280 	.probe		= sh_msiof_spi_probe,
1281 	.remove		= sh_msiof_spi_remove,
1282 	.id_table	= spi_driver_ids,
1283 	.driver		= {
1284 		.name		= "spi_sh_msiof",
1285 		.of_match_table = of_match_ptr(sh_msiof_match),
1286 	},
1287 };
1288 module_platform_driver(sh_msiof_spi_drv);
1289 
1290 MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
1291 MODULE_AUTHOR("Magnus Damm");
1292 MODULE_LICENSE("GPL v2");
1293 MODULE_ALIAS("platform:spi_sh_msiof");
1294