xref: /openbmc/linux/drivers/spi/spi-sh-msiof.c (revision feac8c8b)
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/gpio/consumer.h>
23 #include <linux/interrupt.h>
24 #include <linux/io.h>
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/of.h>
28 #include <linux/of_device.h>
29 #include <linux/platform_device.h>
30 #include <linux/pm_runtime.h>
31 #include <linux/sh_dma.h>
32 
33 #include <linux/spi/sh_msiof.h>
34 #include <linux/spi/spi.h>
35 
36 #include <asm/unaligned.h>
37 
38 struct sh_msiof_chipdata {
39 	u16 tx_fifo_size;
40 	u16 rx_fifo_size;
41 	u16 master_flags;
42 	u16 min_div;
43 };
44 
45 struct sh_msiof_spi_priv {
46 	struct spi_master *master;
47 	void __iomem *mapbase;
48 	struct clk *clk;
49 	struct platform_device *pdev;
50 	struct sh_msiof_spi_info *info;
51 	struct completion done;
52 	unsigned int tx_fifo_size;
53 	unsigned int rx_fifo_size;
54 	unsigned int min_div;
55 	void *tx_dma_page;
56 	void *rx_dma_page;
57 	dma_addr_t tx_dma_addr;
58 	dma_addr_t rx_dma_addr;
59 	unsigned short unused_ss;
60 	bool native_cs_inited;
61 	bool native_cs_high;
62 	bool slave_aborted;
63 };
64 
65 #define MAX_SS	3	/* Maximum number of native chip selects */
66 
67 #define TMDR1	0x00	/* Transmit Mode Register 1 */
68 #define TMDR2	0x04	/* Transmit Mode Register 2 */
69 #define TMDR3	0x08	/* Transmit Mode Register 3 */
70 #define RMDR1	0x10	/* Receive Mode Register 1 */
71 #define RMDR2	0x14	/* Receive Mode Register 2 */
72 #define RMDR3	0x18	/* Receive Mode Register 3 */
73 #define TSCR	0x20	/* Transmit Clock Select Register */
74 #define RSCR	0x22	/* Receive Clock Select Register (SH, A1, APE6) */
75 #define CTR	0x28	/* Control Register */
76 #define FCTR	0x30	/* FIFO Control Register */
77 #define STR	0x40	/* Status Register */
78 #define IER	0x44	/* Interrupt Enable Register */
79 #define TDR1	0x48	/* Transmit Control Data Register 1 (SH, A1) */
80 #define TDR2	0x4c	/* Transmit Control Data Register 2 (SH, A1) */
81 #define TFDR	0x50	/* Transmit FIFO Data Register */
82 #define RDR1	0x58	/* Receive Control Data Register 1 (SH, A1) */
83 #define RDR2	0x5c	/* Receive Control Data Register 2 (SH, A1) */
84 #define RFDR	0x60	/* Receive FIFO Data Register */
85 
86 /* TMDR1 and RMDR1 */
87 #define MDR1_TRMD	 0x80000000 /* Transfer Mode (1 = Master mode) */
88 #define MDR1_SYNCMD_MASK 0x30000000 /* SYNC Mode */
89 #define MDR1_SYNCMD_SPI	 0x20000000 /*   Level mode/SPI */
90 #define MDR1_SYNCMD_LR	 0x30000000 /*   L/R mode */
91 #define MDR1_SYNCAC_SHIFT	 25 /* Sync Polarity (1 = Active-low) */
92 #define MDR1_BITLSB_SHIFT	 24 /* MSB/LSB First (1 = LSB first) */
93 #define MDR1_DTDL_SHIFT		 20 /* Data Pin Bit Delay for MSIOF_SYNC */
94 #define MDR1_SYNCDL_SHIFT	 16 /* Frame Sync Signal Timing Delay */
95 #define MDR1_FLD_MASK	 0x0000000c /* Frame Sync Signal Interval (0-3) */
96 #define MDR1_FLD_SHIFT		  2
97 #define MDR1_XXSTP	 0x00000001 /* Transmission/Reception Stop on FIFO */
98 /* TMDR1 */
99 #define TMDR1_PCON	 0x40000000 /* Transfer Signal Connection */
100 #define TMDR1_SYNCCH_MASK 0xc000000 /* Synchronization Signal Channel Select */
101 #define TMDR1_SYNCCH_SHIFT	 26 /* 0=MSIOF_SYNC, 1=MSIOF_SS1, 2=MSIOF_SS2 */
102 
103 /* TMDR2 and RMDR2 */
104 #define MDR2_BITLEN1(i)	(((i) - 1) << 24) /* Data Size (8-32 bits) */
105 #define MDR2_WDLEN1(i)	(((i) - 1) << 16) /* Word Count (1-64/256 (SH, A1))) */
106 #define MDR2_GRPMASK1	0x00000001 /* Group Output Mask 1 (SH, A1) */
107 
108 /* TSCR and RSCR */
109 #define SCR_BRPS_MASK	    0x1f00 /* Prescaler Setting (1-32) */
110 #define SCR_BRPS(i)	(((i) - 1) << 8)
111 #define SCR_BRDV_MASK	    0x0007 /* Baud Rate Generator's Division Ratio */
112 #define SCR_BRDV_DIV_2	    0x0000
113 #define SCR_BRDV_DIV_4	    0x0001
114 #define SCR_BRDV_DIV_8	    0x0002
115 #define SCR_BRDV_DIV_16	    0x0003
116 #define SCR_BRDV_DIV_32	    0x0004
117 #define SCR_BRDV_DIV_1	    0x0007
118 
119 /* CTR */
120 #define CTR_TSCKIZ_MASK	0xc0000000 /* Transmit Clock I/O Polarity Select */
121 #define CTR_TSCKIZ_SCK	0x80000000 /*   Disable SCK when TX disabled */
122 #define CTR_TSCKIZ_POL_SHIFT	30 /*   Transmit Clock Polarity */
123 #define CTR_RSCKIZ_MASK	0x30000000 /* Receive Clock Polarity Select */
124 #define CTR_RSCKIZ_SCK	0x20000000 /*   Must match CTR_TSCKIZ_SCK */
125 #define CTR_RSCKIZ_POL_SHIFT	28 /*   Receive Clock Polarity */
126 #define CTR_TEDG_SHIFT		27 /* Transmit Timing (1 = falling edge) */
127 #define CTR_REDG_SHIFT		26 /* Receive Timing (1 = falling edge) */
128 #define CTR_TXDIZ_MASK	0x00c00000 /* Pin Output When TX is Disabled */
129 #define CTR_TXDIZ_LOW	0x00000000 /*   0 */
130 #define CTR_TXDIZ_HIGH	0x00400000 /*   1 */
131 #define CTR_TXDIZ_HIZ	0x00800000 /*   High-impedance */
132 #define CTR_TSCKE	0x00008000 /* Transmit Serial Clock Output Enable */
133 #define CTR_TFSE	0x00004000 /* Transmit Frame Sync Signal Output Enable */
134 #define CTR_TXE		0x00000200 /* Transmit Enable */
135 #define CTR_RXE		0x00000100 /* Receive Enable */
136 
137 /* FCTR */
138 #define FCTR_TFWM_MASK	0xe0000000 /* Transmit FIFO Watermark */
139 #define FCTR_TFWM_64	0x00000000 /*  Transfer Request when 64 empty stages */
140 #define FCTR_TFWM_32	0x20000000 /*  Transfer Request when 32 empty stages */
141 #define FCTR_TFWM_24	0x40000000 /*  Transfer Request when 24 empty stages */
142 #define FCTR_TFWM_16	0x60000000 /*  Transfer Request when 16 empty stages */
143 #define FCTR_TFWM_12	0x80000000 /*  Transfer Request when 12 empty stages */
144 #define FCTR_TFWM_8	0xa0000000 /*  Transfer Request when 8 empty stages */
145 #define FCTR_TFWM_4	0xc0000000 /*  Transfer Request when 4 empty stages */
146 #define FCTR_TFWM_1	0xe0000000 /*  Transfer Request when 1 empty stage */
147 #define FCTR_TFUA_MASK	0x07f00000 /* Transmit FIFO Usable Area */
148 #define FCTR_TFUA_SHIFT		20
149 #define FCTR_TFUA(i)	((i) << FCTR_TFUA_SHIFT)
150 #define FCTR_RFWM_MASK	0x0000e000 /* Receive FIFO Watermark */
151 #define FCTR_RFWM_1	0x00000000 /*  Transfer Request when 1 valid stages */
152 #define FCTR_RFWM_4	0x00002000 /*  Transfer Request when 4 valid stages */
153 #define FCTR_RFWM_8	0x00004000 /*  Transfer Request when 8 valid stages */
154 #define FCTR_RFWM_16	0x00006000 /*  Transfer Request when 16 valid stages */
155 #define FCTR_RFWM_32	0x00008000 /*  Transfer Request when 32 valid stages */
156 #define FCTR_RFWM_64	0x0000a000 /*  Transfer Request when 64 valid stages */
157 #define FCTR_RFWM_128	0x0000c000 /*  Transfer Request when 128 valid stages */
158 #define FCTR_RFWM_256	0x0000e000 /*  Transfer Request when 256 valid stages */
159 #define FCTR_RFUA_MASK	0x00001ff0 /* Receive FIFO Usable Area (0x40 = full) */
160 #define FCTR_RFUA_SHIFT		 4
161 #define FCTR_RFUA(i)	((i) << FCTR_RFUA_SHIFT)
162 
163 /* STR */
164 #define STR_TFEMP	0x20000000 /* Transmit FIFO Empty */
165 #define STR_TDREQ	0x10000000 /* Transmit Data Transfer Request */
166 #define STR_TEOF	0x00800000 /* Frame Transmission End */
167 #define STR_TFSERR	0x00200000 /* Transmit Frame Synchronization Error */
168 #define STR_TFOVF	0x00100000 /* Transmit FIFO Overflow */
169 #define STR_TFUDF	0x00080000 /* Transmit FIFO Underflow */
170 #define STR_RFFUL	0x00002000 /* Receive FIFO Full */
171 #define STR_RDREQ	0x00001000 /* Receive Data Transfer Request */
172 #define STR_REOF	0x00000080 /* Frame Reception End */
173 #define STR_RFSERR	0x00000020 /* Receive Frame Synchronization Error */
174 #define STR_RFUDF	0x00000010 /* Receive FIFO Underflow */
175 #define STR_RFOVF	0x00000008 /* Receive FIFO Overflow */
176 
177 /* IER */
178 #define IER_TDMAE	0x80000000 /* Transmit Data DMA Transfer Req. Enable */
179 #define IER_TFEMPE	0x20000000 /* Transmit FIFO Empty Enable */
180 #define IER_TDREQE	0x10000000 /* Transmit Data Transfer Request Enable */
181 #define IER_TEOFE	0x00800000 /* Frame Transmission End Enable */
182 #define IER_TFSERRE	0x00200000 /* Transmit Frame Sync Error Enable */
183 #define IER_TFOVFE	0x00100000 /* Transmit FIFO Overflow Enable */
184 #define IER_TFUDFE	0x00080000 /* Transmit FIFO Underflow Enable */
185 #define IER_RDMAE	0x00008000 /* Receive Data DMA Transfer Req. Enable */
186 #define IER_RFFULE	0x00002000 /* Receive FIFO Full Enable */
187 #define IER_RDREQE	0x00001000 /* Receive Data Transfer Request Enable */
188 #define IER_REOFE	0x00000080 /* Frame Reception End Enable */
189 #define IER_RFSERRE	0x00000020 /* Receive Frame Sync Error Enable */
190 #define IER_RFUDFE	0x00000010 /* Receive FIFO Underflow Enable */
191 #define IER_RFOVFE	0x00000008 /* Receive FIFO Overflow Enable */
192 
193 
194 static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs)
195 {
196 	switch (reg_offs) {
197 	case TSCR:
198 	case RSCR:
199 		return ioread16(p->mapbase + reg_offs);
200 	default:
201 		return ioread32(p->mapbase + reg_offs);
202 	}
203 }
204 
205 static void sh_msiof_write(struct sh_msiof_spi_priv *p, int reg_offs,
206 			   u32 value)
207 {
208 	switch (reg_offs) {
209 	case TSCR:
210 	case RSCR:
211 		iowrite16(value, p->mapbase + reg_offs);
212 		break;
213 	default:
214 		iowrite32(value, p->mapbase + reg_offs);
215 		break;
216 	}
217 }
218 
219 static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv *p,
220 				    u32 clr, u32 set)
221 {
222 	u32 mask = clr | set;
223 	u32 data;
224 	int k;
225 
226 	data = sh_msiof_read(p, CTR);
227 	data &= ~clr;
228 	data |= set;
229 	sh_msiof_write(p, CTR, data);
230 
231 	for (k = 100; k > 0; k--) {
232 		if ((sh_msiof_read(p, CTR) & mask) == set)
233 			break;
234 
235 		udelay(10);
236 	}
237 
238 	return k > 0 ? 0 : -ETIMEDOUT;
239 }
240 
241 static irqreturn_t sh_msiof_spi_irq(int irq, void *data)
242 {
243 	struct sh_msiof_spi_priv *p = data;
244 
245 	/* just disable the interrupt and wake up */
246 	sh_msiof_write(p, IER, 0);
247 	complete(&p->done);
248 
249 	return IRQ_HANDLED;
250 }
251 
252 static struct {
253 	unsigned short div;
254 	unsigned short brdv;
255 } const sh_msiof_spi_div_table[] = {
256 	{ 1,	SCR_BRDV_DIV_1 },
257 	{ 2,	SCR_BRDV_DIV_2 },
258 	{ 4,	SCR_BRDV_DIV_4 },
259 	{ 8,	SCR_BRDV_DIV_8 },
260 	{ 16,	SCR_BRDV_DIV_16 },
261 	{ 32,	SCR_BRDV_DIV_32 },
262 };
263 
264 static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
265 				      unsigned long parent_rate, u32 spi_hz)
266 {
267 	unsigned long div = 1024;
268 	u32 brps, scr;
269 	size_t k;
270 
271 	if (!WARN_ON(!spi_hz || !parent_rate))
272 		div = DIV_ROUND_UP(parent_rate, spi_hz);
273 
274 	div = max_t(unsigned long, div, p->min_div);
275 
276 	for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_div_table); k++) {
277 		brps = DIV_ROUND_UP(div, sh_msiof_spi_div_table[k].div);
278 		/* SCR_BRDV_DIV_1 is valid only if BRPS is x 1/1 or x 1/2 */
279 		if (sh_msiof_spi_div_table[k].div == 1 && brps > 2)
280 			continue;
281 		if (brps <= 32) /* max of brdv is 32 */
282 			break;
283 	}
284 
285 	k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_div_table) - 1);
286 
287 	scr = sh_msiof_spi_div_table[k].brdv | SCR_BRPS(brps);
288 	sh_msiof_write(p, TSCR, scr);
289 	if (!(p->master->flags & SPI_MASTER_MUST_TX))
290 		sh_msiof_write(p, RSCR, scr);
291 }
292 
293 static u32 sh_msiof_get_delay_bit(u32 dtdl_or_syncdl)
294 {
295 	/*
296 	 * DTDL/SYNCDL bit	: p->info->dtdl or p->info->syncdl
297 	 * b'000		: 0
298 	 * b'001		: 100
299 	 * b'010		: 200
300 	 * b'011 (SYNCDL only)	: 300
301 	 * b'101		: 50
302 	 * b'110		: 150
303 	 */
304 	if (dtdl_or_syncdl % 100)
305 		return dtdl_or_syncdl / 100 + 5;
306 	else
307 		return dtdl_or_syncdl / 100;
308 }
309 
310 static u32 sh_msiof_spi_get_dtdl_and_syncdl(struct sh_msiof_spi_priv *p)
311 {
312 	u32 val;
313 
314 	if (!p->info)
315 		return 0;
316 
317 	/* check if DTDL and SYNCDL is allowed value */
318 	if (p->info->dtdl > 200 || p->info->syncdl > 300) {
319 		dev_warn(&p->pdev->dev, "DTDL or SYNCDL is too large\n");
320 		return 0;
321 	}
322 
323 	/* check if the sum of DTDL and SYNCDL becomes an integer value  */
324 	if ((p->info->dtdl + p->info->syncdl) % 100) {
325 		dev_warn(&p->pdev->dev, "the sum of DTDL/SYNCDL is not good\n");
326 		return 0;
327 	}
328 
329 	val = sh_msiof_get_delay_bit(p->info->dtdl) << MDR1_DTDL_SHIFT;
330 	val |= sh_msiof_get_delay_bit(p->info->syncdl) << MDR1_SYNCDL_SHIFT;
331 
332 	return val;
333 }
334 
335 static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p, u32 ss,
336 				      u32 cpol, u32 cpha,
337 				      u32 tx_hi_z, u32 lsb_first, u32 cs_high)
338 {
339 	u32 tmp;
340 	int edge;
341 
342 	/*
343 	 * CPOL CPHA     TSCKIZ RSCKIZ TEDG REDG
344 	 *    0    0         10     10    1    1
345 	 *    0    1         10     10    0    0
346 	 *    1    0         11     11    0    0
347 	 *    1    1         11     11    1    1
348 	 */
349 	tmp = MDR1_SYNCMD_SPI | 1 << MDR1_FLD_SHIFT | MDR1_XXSTP;
350 	tmp |= !cs_high << MDR1_SYNCAC_SHIFT;
351 	tmp |= lsb_first << MDR1_BITLSB_SHIFT;
352 	tmp |= sh_msiof_spi_get_dtdl_and_syncdl(p);
353 	if (spi_controller_is_slave(p->master)) {
354 		sh_msiof_write(p, TMDR1, tmp | TMDR1_PCON);
355 	} else {
356 		sh_msiof_write(p, TMDR1,
357 			       tmp | MDR1_TRMD | TMDR1_PCON |
358 			       (ss < MAX_SS ? ss : 0) << TMDR1_SYNCCH_SHIFT);
359 	}
360 	if (p->master->flags & SPI_MASTER_MUST_TX) {
361 		/* These bits are reserved if RX needs TX */
362 		tmp &= ~0x0000ffff;
363 	}
364 	sh_msiof_write(p, RMDR1, tmp);
365 
366 	tmp = 0;
367 	tmp |= CTR_TSCKIZ_SCK | cpol << CTR_TSCKIZ_POL_SHIFT;
368 	tmp |= CTR_RSCKIZ_SCK | cpol << CTR_RSCKIZ_POL_SHIFT;
369 
370 	edge = cpol ^ !cpha;
371 
372 	tmp |= edge << CTR_TEDG_SHIFT;
373 	tmp |= edge << CTR_REDG_SHIFT;
374 	tmp |= tx_hi_z ? CTR_TXDIZ_HIZ : CTR_TXDIZ_LOW;
375 	sh_msiof_write(p, CTR, tmp);
376 }
377 
378 static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
379 				       const void *tx_buf, void *rx_buf,
380 				       u32 bits, u32 words)
381 {
382 	u32 dr2 = MDR2_BITLEN1(bits) | MDR2_WDLEN1(words);
383 
384 	if (tx_buf || (p->master->flags & SPI_MASTER_MUST_TX))
385 		sh_msiof_write(p, TMDR2, dr2);
386 	else
387 		sh_msiof_write(p, TMDR2, dr2 | MDR2_GRPMASK1);
388 
389 	if (rx_buf)
390 		sh_msiof_write(p, RMDR2, dr2);
391 }
392 
393 static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
394 {
395 	sh_msiof_write(p, STR, sh_msiof_read(p, STR));
396 }
397 
398 static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
399 				      const void *tx_buf, int words, int fs)
400 {
401 	const u8 *buf_8 = tx_buf;
402 	int k;
403 
404 	for (k = 0; k < words; k++)
405 		sh_msiof_write(p, TFDR, buf_8[k] << fs);
406 }
407 
408 static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
409 				       const void *tx_buf, int words, int fs)
410 {
411 	const u16 *buf_16 = tx_buf;
412 	int k;
413 
414 	for (k = 0; k < words; k++)
415 		sh_msiof_write(p, TFDR, buf_16[k] << fs);
416 }
417 
418 static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
419 					const void *tx_buf, int words, int fs)
420 {
421 	const u16 *buf_16 = tx_buf;
422 	int k;
423 
424 	for (k = 0; k < words; k++)
425 		sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
426 }
427 
428 static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
429 				       const void *tx_buf, int words, int fs)
430 {
431 	const u32 *buf_32 = tx_buf;
432 	int k;
433 
434 	for (k = 0; k < words; k++)
435 		sh_msiof_write(p, TFDR, buf_32[k] << fs);
436 }
437 
438 static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
439 					const void *tx_buf, int words, int fs)
440 {
441 	const u32 *buf_32 = tx_buf;
442 	int k;
443 
444 	for (k = 0; k < words; k++)
445 		sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
446 }
447 
448 static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
449 					const void *tx_buf, int words, int fs)
450 {
451 	const u32 *buf_32 = tx_buf;
452 	int k;
453 
454 	for (k = 0; k < words; k++)
455 		sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
456 }
457 
458 static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
459 					 const void *tx_buf, int words, int fs)
460 {
461 	const u32 *buf_32 = tx_buf;
462 	int k;
463 
464 	for (k = 0; k < words; k++)
465 		sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
466 }
467 
468 static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
469 				     void *rx_buf, int words, int fs)
470 {
471 	u8 *buf_8 = rx_buf;
472 	int k;
473 
474 	for (k = 0; k < words; k++)
475 		buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
476 }
477 
478 static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
479 				      void *rx_buf, int words, int fs)
480 {
481 	u16 *buf_16 = rx_buf;
482 	int k;
483 
484 	for (k = 0; k < words; k++)
485 		buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
486 }
487 
488 static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
489 				       void *rx_buf, int words, int fs)
490 {
491 	u16 *buf_16 = rx_buf;
492 	int k;
493 
494 	for (k = 0; k < words; k++)
495 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
496 }
497 
498 static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
499 				      void *rx_buf, int words, int fs)
500 {
501 	u32 *buf_32 = rx_buf;
502 	int k;
503 
504 	for (k = 0; k < words; k++)
505 		buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
506 }
507 
508 static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
509 				       void *rx_buf, int words, int fs)
510 {
511 	u32 *buf_32 = rx_buf;
512 	int k;
513 
514 	for (k = 0; k < words; k++)
515 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
516 }
517 
518 static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
519 				       void *rx_buf, int words, int fs)
520 {
521 	u32 *buf_32 = rx_buf;
522 	int k;
523 
524 	for (k = 0; k < words; k++)
525 		buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
526 }
527 
528 static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
529 				       void *rx_buf, int words, int fs)
530 {
531 	u32 *buf_32 = rx_buf;
532 	int k;
533 
534 	for (k = 0; k < words; k++)
535 		put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
536 }
537 
538 static int sh_msiof_spi_setup(struct spi_device *spi)
539 {
540 	struct device_node	*np = spi->master->dev.of_node;
541 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
542 	u32 clr, set, tmp;
543 
544 	if (!np) {
545 		/*
546 		 * Use spi->controller_data for CS (same strategy as spi_gpio),
547 		 * if any. otherwise let HW control CS
548 		 */
549 		spi->cs_gpio = (uintptr_t)spi->controller_data;
550 	}
551 
552 	if (gpio_is_valid(spi->cs_gpio)) {
553 		gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
554 		return 0;
555 	}
556 
557 	if (spi_controller_is_slave(p->master))
558 		return 0;
559 
560 	if (p->native_cs_inited &&
561 	    (p->native_cs_high == !!(spi->mode & SPI_CS_HIGH)))
562 		return 0;
563 
564 	/* Configure native chip select mode/polarity early */
565 	clr = MDR1_SYNCMD_MASK;
566 	set = MDR1_TRMD | TMDR1_PCON | MDR1_SYNCMD_SPI;
567 	if (spi->mode & SPI_CS_HIGH)
568 		clr |= BIT(MDR1_SYNCAC_SHIFT);
569 	else
570 		set |= BIT(MDR1_SYNCAC_SHIFT);
571 	pm_runtime_get_sync(&p->pdev->dev);
572 	tmp = sh_msiof_read(p, TMDR1) & ~clr;
573 	sh_msiof_write(p, TMDR1, tmp | set);
574 	pm_runtime_put(&p->pdev->dev);
575 	p->native_cs_high = spi->mode & SPI_CS_HIGH;
576 	p->native_cs_inited = true;
577 	return 0;
578 }
579 
580 static int sh_msiof_prepare_message(struct spi_master *master,
581 				    struct spi_message *msg)
582 {
583 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
584 	const struct spi_device *spi = msg->spi;
585 	u32 ss, cs_high;
586 
587 	/* Configure pins before asserting CS */
588 	if (gpio_is_valid(spi->cs_gpio)) {
589 		ss = p->unused_ss;
590 		cs_high = p->native_cs_high;
591 	} else {
592 		ss = spi->chip_select;
593 		cs_high = !!(spi->mode & SPI_CS_HIGH);
594 	}
595 	sh_msiof_spi_set_pin_regs(p, ss, !!(spi->mode & SPI_CPOL),
596 				  !!(spi->mode & SPI_CPHA),
597 				  !!(spi->mode & SPI_3WIRE),
598 				  !!(spi->mode & SPI_LSB_FIRST), cs_high);
599 	return 0;
600 }
601 
602 static int sh_msiof_spi_start(struct sh_msiof_spi_priv *p, void *rx_buf)
603 {
604 	bool slave = spi_controller_is_slave(p->master);
605 	int ret = 0;
606 
607 	/* setup clock and rx/tx signals */
608 	if (!slave)
609 		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
610 	if (rx_buf && !ret)
611 		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
612 	if (!ret)
613 		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);
614 
615 	/* start by setting frame bit */
616 	if (!ret && !slave)
617 		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
618 
619 	return ret;
620 }
621 
622 static int sh_msiof_spi_stop(struct sh_msiof_spi_priv *p, void *rx_buf)
623 {
624 	bool slave = spi_controller_is_slave(p->master);
625 	int ret = 0;
626 
627 	/* shut down frame, rx/tx and clock signals */
628 	if (!slave)
629 		ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
630 	if (!ret)
631 		ret = sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
632 	if (rx_buf && !ret)
633 		ret = sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
634 	if (!ret && !slave)
635 		ret = sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
636 
637 	return ret;
638 }
639 
640 static int sh_msiof_slave_abort(struct spi_master *master)
641 {
642 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
643 
644 	p->slave_aborted = true;
645 	complete(&p->done);
646 	return 0;
647 }
648 
649 static int sh_msiof_wait_for_completion(struct sh_msiof_spi_priv *p)
650 {
651 	if (spi_controller_is_slave(p->master)) {
652 		if (wait_for_completion_interruptible(&p->done) ||
653 		    p->slave_aborted) {
654 			dev_dbg(&p->pdev->dev, "interrupted\n");
655 			return -EINTR;
656 		}
657 	} else {
658 		if (!wait_for_completion_timeout(&p->done, HZ)) {
659 			dev_err(&p->pdev->dev, "timeout\n");
660 			return -ETIMEDOUT;
661 		}
662 	}
663 
664 	return 0;
665 }
666 
667 static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
668 				  void (*tx_fifo)(struct sh_msiof_spi_priv *,
669 						  const void *, int, int),
670 				  void (*rx_fifo)(struct sh_msiof_spi_priv *,
671 						  void *, int, int),
672 				  const void *tx_buf, void *rx_buf,
673 				  int words, int bits)
674 {
675 	int fifo_shift;
676 	int ret;
677 
678 	/* limit maximum word transfer to rx/tx fifo size */
679 	if (tx_buf)
680 		words = min_t(int, words, p->tx_fifo_size);
681 	if (rx_buf)
682 		words = min_t(int, words, p->rx_fifo_size);
683 
684 	/* the fifo contents need shifting */
685 	fifo_shift = 32 - bits;
686 
687 	/* default FIFO watermarks for PIO */
688 	sh_msiof_write(p, FCTR, 0);
689 
690 	/* setup msiof transfer mode registers */
691 	sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);
692 	sh_msiof_write(p, IER, IER_TEOFE | IER_REOFE);
693 
694 	/* write tx fifo */
695 	if (tx_buf)
696 		tx_fifo(p, tx_buf, words, fifo_shift);
697 
698 	reinit_completion(&p->done);
699 	p->slave_aborted = false;
700 
701 	ret = sh_msiof_spi_start(p, rx_buf);
702 	if (ret) {
703 		dev_err(&p->pdev->dev, "failed to start hardware\n");
704 		goto stop_ier;
705 	}
706 
707 	/* wait for tx fifo to be emptied / rx fifo to be filled */
708 	ret = sh_msiof_wait_for_completion(p);
709 	if (ret)
710 		goto stop_reset;
711 
712 	/* read rx fifo */
713 	if (rx_buf)
714 		rx_fifo(p, rx_buf, words, fifo_shift);
715 
716 	/* clear status bits */
717 	sh_msiof_reset_str(p);
718 
719 	ret = sh_msiof_spi_stop(p, rx_buf);
720 	if (ret) {
721 		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
722 		return ret;
723 	}
724 
725 	return words;
726 
727 stop_reset:
728 	sh_msiof_reset_str(p);
729 	sh_msiof_spi_stop(p, rx_buf);
730 stop_ier:
731 	sh_msiof_write(p, IER, 0);
732 	return ret;
733 }
734 
735 static void sh_msiof_dma_complete(void *arg)
736 {
737 	struct sh_msiof_spi_priv *p = arg;
738 
739 	sh_msiof_write(p, IER, 0);
740 	complete(&p->done);
741 }
742 
743 static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
744 			     void *rx, unsigned int len)
745 {
746 	u32 ier_bits = 0;
747 	struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
748 	dma_cookie_t cookie;
749 	int ret;
750 
751 	/* First prepare and submit the DMA request(s), as this may fail */
752 	if (rx) {
753 		ier_bits |= IER_RDREQE | IER_RDMAE;
754 		desc_rx = dmaengine_prep_slave_single(p->master->dma_rx,
755 					p->rx_dma_addr, len, DMA_FROM_DEVICE,
756 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
757 		if (!desc_rx)
758 			return -EAGAIN;
759 
760 		desc_rx->callback = sh_msiof_dma_complete;
761 		desc_rx->callback_param = p;
762 		cookie = dmaengine_submit(desc_rx);
763 		if (dma_submit_error(cookie))
764 			return cookie;
765 	}
766 
767 	if (tx) {
768 		ier_bits |= IER_TDREQE | IER_TDMAE;
769 		dma_sync_single_for_device(p->master->dma_tx->device->dev,
770 					   p->tx_dma_addr, len, DMA_TO_DEVICE);
771 		desc_tx = dmaengine_prep_slave_single(p->master->dma_tx,
772 					p->tx_dma_addr, len, DMA_TO_DEVICE,
773 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
774 		if (!desc_tx) {
775 			ret = -EAGAIN;
776 			goto no_dma_tx;
777 		}
778 
779 		if (rx) {
780 			/* No callback */
781 			desc_tx->callback = NULL;
782 		} else {
783 			desc_tx->callback = sh_msiof_dma_complete;
784 			desc_tx->callback_param = p;
785 		}
786 		cookie = dmaengine_submit(desc_tx);
787 		if (dma_submit_error(cookie)) {
788 			ret = cookie;
789 			goto no_dma_tx;
790 		}
791 	}
792 
793 	/* 1 stage FIFO watermarks for DMA */
794 	sh_msiof_write(p, FCTR, FCTR_TFWM_1 | FCTR_RFWM_1);
795 
796 	/* setup msiof transfer mode registers (32-bit words) */
797 	sh_msiof_spi_set_mode_regs(p, tx, rx, 32, len / 4);
798 
799 	sh_msiof_write(p, IER, ier_bits);
800 
801 	reinit_completion(&p->done);
802 	p->slave_aborted = false;
803 
804 	/* Now start DMA */
805 	if (rx)
806 		dma_async_issue_pending(p->master->dma_rx);
807 	if (tx)
808 		dma_async_issue_pending(p->master->dma_tx);
809 
810 	ret = sh_msiof_spi_start(p, rx);
811 	if (ret) {
812 		dev_err(&p->pdev->dev, "failed to start hardware\n");
813 		goto stop_dma;
814 	}
815 
816 	/* wait for tx/rx DMA completion */
817 	ret = sh_msiof_wait_for_completion(p);
818 	if (ret)
819 		goto stop_reset;
820 
821 	if (!rx) {
822 		reinit_completion(&p->done);
823 		sh_msiof_write(p, IER, IER_TEOFE);
824 
825 		/* wait for tx fifo to be emptied */
826 		ret = sh_msiof_wait_for_completion(p);
827 		if (ret)
828 			goto stop_reset;
829 	}
830 
831 	/* clear status bits */
832 	sh_msiof_reset_str(p);
833 
834 	ret = sh_msiof_spi_stop(p, rx);
835 	if (ret) {
836 		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
837 		return ret;
838 	}
839 
840 	if (rx)
841 		dma_sync_single_for_cpu(p->master->dma_rx->device->dev,
842 					p->rx_dma_addr, len,
843 					DMA_FROM_DEVICE);
844 
845 	return 0;
846 
847 stop_reset:
848 	sh_msiof_reset_str(p);
849 	sh_msiof_spi_stop(p, rx);
850 stop_dma:
851 	if (tx)
852 		dmaengine_terminate_all(p->master->dma_tx);
853 no_dma_tx:
854 	if (rx)
855 		dmaengine_terminate_all(p->master->dma_rx);
856 	sh_msiof_write(p, IER, 0);
857 	return ret;
858 }
859 
860 static void copy_bswap32(u32 *dst, const u32 *src, unsigned int words)
861 {
862 	/* src or dst can be unaligned, but not both */
863 	if ((unsigned long)src & 3) {
864 		while (words--) {
865 			*dst++ = swab32(get_unaligned(src));
866 			src++;
867 		}
868 	} else if ((unsigned long)dst & 3) {
869 		while (words--) {
870 			put_unaligned(swab32(*src++), dst);
871 			dst++;
872 		}
873 	} else {
874 		while (words--)
875 			*dst++ = swab32(*src++);
876 	}
877 }
878 
879 static void copy_wswap32(u32 *dst, const u32 *src, unsigned int words)
880 {
881 	/* src or dst can be unaligned, but not both */
882 	if ((unsigned long)src & 3) {
883 		while (words--) {
884 			*dst++ = swahw32(get_unaligned(src));
885 			src++;
886 		}
887 	} else if ((unsigned long)dst & 3) {
888 		while (words--) {
889 			put_unaligned(swahw32(*src++), dst);
890 			dst++;
891 		}
892 	} else {
893 		while (words--)
894 			*dst++ = swahw32(*src++);
895 	}
896 }
897 
898 static void copy_plain32(u32 *dst, const u32 *src, unsigned int words)
899 {
900 	memcpy(dst, src, words * 4);
901 }
902 
903 static int sh_msiof_transfer_one(struct spi_master *master,
904 				 struct spi_device *spi,
905 				 struct spi_transfer *t)
906 {
907 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
908 	void (*copy32)(u32 *, const u32 *, unsigned int);
909 	void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
910 	void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
911 	const void *tx_buf = t->tx_buf;
912 	void *rx_buf = t->rx_buf;
913 	unsigned int len = t->len;
914 	unsigned int bits = t->bits_per_word;
915 	unsigned int bytes_per_word;
916 	unsigned int words;
917 	int n;
918 	bool swab;
919 	int ret;
920 
921 	/* setup clocks (clock already enabled in chipselect()) */
922 	if (!spi_controller_is_slave(p->master))
923 		sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk), t->speed_hz);
924 
925 	while (master->dma_tx && len > 15) {
926 		/*
927 		 *  DMA supports 32-bit words only, hence pack 8-bit and 16-bit
928 		 *  words, with byte resp. word swapping.
929 		 */
930 		unsigned int l = 0;
931 
932 		if (tx_buf)
933 			l = min(len, p->tx_fifo_size * 4);
934 		if (rx_buf)
935 			l = min(len, p->rx_fifo_size * 4);
936 
937 		if (bits <= 8) {
938 			if (l & 3)
939 				break;
940 			copy32 = copy_bswap32;
941 		} else if (bits <= 16) {
942 			if (l & 3)
943 				break;
944 			copy32 = copy_wswap32;
945 		} else {
946 			copy32 = copy_plain32;
947 		}
948 
949 		if (tx_buf)
950 			copy32(p->tx_dma_page, tx_buf, l / 4);
951 
952 		ret = sh_msiof_dma_once(p, tx_buf, rx_buf, l);
953 		if (ret == -EAGAIN) {
954 			dev_warn_once(&p->pdev->dev,
955 				"DMA not available, falling back to PIO\n");
956 			break;
957 		}
958 		if (ret)
959 			return ret;
960 
961 		if (rx_buf) {
962 			copy32(rx_buf, p->rx_dma_page, l / 4);
963 			rx_buf += l;
964 		}
965 		if (tx_buf)
966 			tx_buf += l;
967 
968 		len -= l;
969 		if (!len)
970 			return 0;
971 	}
972 
973 	if (bits <= 8 && len > 15 && !(len & 3)) {
974 		bits = 32;
975 		swab = true;
976 	} else {
977 		swab = false;
978 	}
979 
980 	/* setup bytes per word and fifo read/write functions */
981 	if (bits <= 8) {
982 		bytes_per_word = 1;
983 		tx_fifo = sh_msiof_spi_write_fifo_8;
984 		rx_fifo = sh_msiof_spi_read_fifo_8;
985 	} else if (bits <= 16) {
986 		bytes_per_word = 2;
987 		if ((unsigned long)tx_buf & 0x01)
988 			tx_fifo = sh_msiof_spi_write_fifo_16u;
989 		else
990 			tx_fifo = sh_msiof_spi_write_fifo_16;
991 
992 		if ((unsigned long)rx_buf & 0x01)
993 			rx_fifo = sh_msiof_spi_read_fifo_16u;
994 		else
995 			rx_fifo = sh_msiof_spi_read_fifo_16;
996 	} else if (swab) {
997 		bytes_per_word = 4;
998 		if ((unsigned long)tx_buf & 0x03)
999 			tx_fifo = sh_msiof_spi_write_fifo_s32u;
1000 		else
1001 			tx_fifo = sh_msiof_spi_write_fifo_s32;
1002 
1003 		if ((unsigned long)rx_buf & 0x03)
1004 			rx_fifo = sh_msiof_spi_read_fifo_s32u;
1005 		else
1006 			rx_fifo = sh_msiof_spi_read_fifo_s32;
1007 	} else {
1008 		bytes_per_word = 4;
1009 		if ((unsigned long)tx_buf & 0x03)
1010 			tx_fifo = sh_msiof_spi_write_fifo_32u;
1011 		else
1012 			tx_fifo = sh_msiof_spi_write_fifo_32;
1013 
1014 		if ((unsigned long)rx_buf & 0x03)
1015 			rx_fifo = sh_msiof_spi_read_fifo_32u;
1016 		else
1017 			rx_fifo = sh_msiof_spi_read_fifo_32;
1018 	}
1019 
1020 	/* transfer in fifo sized chunks */
1021 	words = len / bytes_per_word;
1022 
1023 	while (words > 0) {
1024 		n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo, tx_buf, rx_buf,
1025 					   words, bits);
1026 		if (n < 0)
1027 			return n;
1028 
1029 		if (tx_buf)
1030 			tx_buf += n * bytes_per_word;
1031 		if (rx_buf)
1032 			rx_buf += n * bytes_per_word;
1033 		words -= n;
1034 	}
1035 
1036 	return 0;
1037 }
1038 
1039 static const struct sh_msiof_chipdata sh_data = {
1040 	.tx_fifo_size = 64,
1041 	.rx_fifo_size = 64,
1042 	.master_flags = 0,
1043 	.min_div = 1,
1044 };
1045 
1046 static const struct sh_msiof_chipdata rcar_gen2_data = {
1047 	.tx_fifo_size = 64,
1048 	.rx_fifo_size = 64,
1049 	.master_flags = SPI_MASTER_MUST_TX,
1050 	.min_div = 1,
1051 };
1052 
1053 static const struct sh_msiof_chipdata rcar_gen3_data = {
1054 	.tx_fifo_size = 64,
1055 	.rx_fifo_size = 64,
1056 	.master_flags = SPI_MASTER_MUST_TX,
1057 	.min_div = 2,
1058 };
1059 
1060 static const struct of_device_id sh_msiof_match[] = {
1061 	{ .compatible = "renesas,sh-mobile-msiof", .data = &sh_data },
1062 	{ .compatible = "renesas,msiof-r8a7743",   .data = &rcar_gen2_data },
1063 	{ .compatible = "renesas,msiof-r8a7745",   .data = &rcar_gen2_data },
1064 	{ .compatible = "renesas,msiof-r8a7790",   .data = &rcar_gen2_data },
1065 	{ .compatible = "renesas,msiof-r8a7791",   .data = &rcar_gen2_data },
1066 	{ .compatible = "renesas,msiof-r8a7792",   .data = &rcar_gen2_data },
1067 	{ .compatible = "renesas,msiof-r8a7793",   .data = &rcar_gen2_data },
1068 	{ .compatible = "renesas,msiof-r8a7794",   .data = &rcar_gen2_data },
1069 	{ .compatible = "renesas,rcar-gen2-msiof", .data = &rcar_gen2_data },
1070 	{ .compatible = "renesas,msiof-r8a7796",   .data = &rcar_gen3_data },
1071 	{ .compatible = "renesas,rcar-gen3-msiof", .data = &rcar_gen3_data },
1072 	{ .compatible = "renesas,sh-msiof",        .data = &sh_data }, /* Deprecated */
1073 	{},
1074 };
1075 MODULE_DEVICE_TABLE(of, sh_msiof_match);
1076 
1077 #ifdef CONFIG_OF
1078 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
1079 {
1080 	struct sh_msiof_spi_info *info;
1081 	struct device_node *np = dev->of_node;
1082 	u32 num_cs = 1;
1083 
1084 	info = devm_kzalloc(dev, sizeof(struct sh_msiof_spi_info), GFP_KERNEL);
1085 	if (!info)
1086 		return NULL;
1087 
1088 	info->mode = of_property_read_bool(np, "spi-slave") ? MSIOF_SPI_SLAVE
1089 							    : MSIOF_SPI_MASTER;
1090 
1091 	/* Parse the MSIOF properties */
1092 	if (info->mode == MSIOF_SPI_MASTER)
1093 		of_property_read_u32(np, "num-cs", &num_cs);
1094 	of_property_read_u32(np, "renesas,tx-fifo-size",
1095 					&info->tx_fifo_override);
1096 	of_property_read_u32(np, "renesas,rx-fifo-size",
1097 					&info->rx_fifo_override);
1098 	of_property_read_u32(np, "renesas,dtdl", &info->dtdl);
1099 	of_property_read_u32(np, "renesas,syncdl", &info->syncdl);
1100 
1101 	info->num_chipselect = num_cs;
1102 
1103 	return info;
1104 }
1105 #else
1106 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
1107 {
1108 	return NULL;
1109 }
1110 #endif
1111 
1112 static int sh_msiof_get_cs_gpios(struct sh_msiof_spi_priv *p)
1113 {
1114 	struct device *dev = &p->pdev->dev;
1115 	unsigned int used_ss_mask = 0;
1116 	unsigned int cs_gpios = 0;
1117 	unsigned int num_cs, i;
1118 	int ret;
1119 
1120 	ret = gpiod_count(dev, "cs");
1121 	if (ret <= 0)
1122 		return 0;
1123 
1124 	num_cs = max_t(unsigned int, ret, p->master->num_chipselect);
1125 	for (i = 0; i < num_cs; i++) {
1126 		struct gpio_desc *gpiod;
1127 
1128 		gpiod = devm_gpiod_get_index(dev, "cs", i, GPIOD_ASIS);
1129 		if (!IS_ERR(gpiod)) {
1130 			cs_gpios++;
1131 			continue;
1132 		}
1133 
1134 		if (PTR_ERR(gpiod) != -ENOENT)
1135 			return PTR_ERR(gpiod);
1136 
1137 		if (i >= MAX_SS) {
1138 			dev_err(dev, "Invalid native chip select %d\n", i);
1139 			return -EINVAL;
1140 		}
1141 		used_ss_mask |= BIT(i);
1142 	}
1143 	p->unused_ss = ffz(used_ss_mask);
1144 	if (cs_gpios && p->unused_ss >= MAX_SS) {
1145 		dev_err(dev, "No unused native chip select available\n");
1146 		return -EINVAL;
1147 	}
1148 	return 0;
1149 }
1150 
1151 static struct dma_chan *sh_msiof_request_dma_chan(struct device *dev,
1152 	enum dma_transfer_direction dir, unsigned int id, dma_addr_t port_addr)
1153 {
1154 	dma_cap_mask_t mask;
1155 	struct dma_chan *chan;
1156 	struct dma_slave_config cfg;
1157 	int ret;
1158 
1159 	dma_cap_zero(mask);
1160 	dma_cap_set(DMA_SLAVE, mask);
1161 
1162 	chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
1163 				(void *)(unsigned long)id, dev,
1164 				dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1165 	if (!chan) {
1166 		dev_warn(dev, "dma_request_slave_channel_compat failed\n");
1167 		return NULL;
1168 	}
1169 
1170 	memset(&cfg, 0, sizeof(cfg));
1171 	cfg.direction = dir;
1172 	if (dir == DMA_MEM_TO_DEV) {
1173 		cfg.dst_addr = port_addr;
1174 		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1175 	} else {
1176 		cfg.src_addr = port_addr;
1177 		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1178 	}
1179 
1180 	ret = dmaengine_slave_config(chan, &cfg);
1181 	if (ret) {
1182 		dev_warn(dev, "dmaengine_slave_config failed %d\n", ret);
1183 		dma_release_channel(chan);
1184 		return NULL;
1185 	}
1186 
1187 	return chan;
1188 }
1189 
1190 static int sh_msiof_request_dma(struct sh_msiof_spi_priv *p)
1191 {
1192 	struct platform_device *pdev = p->pdev;
1193 	struct device *dev = &pdev->dev;
1194 	const struct sh_msiof_spi_info *info = dev_get_platdata(dev);
1195 	unsigned int dma_tx_id, dma_rx_id;
1196 	const struct resource *res;
1197 	struct spi_master *master;
1198 	struct device *tx_dev, *rx_dev;
1199 
1200 	if (dev->of_node) {
1201 		/* In the OF case we will get the slave IDs from the DT */
1202 		dma_tx_id = 0;
1203 		dma_rx_id = 0;
1204 	} else if (info && info->dma_tx_id && info->dma_rx_id) {
1205 		dma_tx_id = info->dma_tx_id;
1206 		dma_rx_id = info->dma_rx_id;
1207 	} else {
1208 		/* The driver assumes no error */
1209 		return 0;
1210 	}
1211 
1212 	/* The DMA engine uses the second register set, if present */
1213 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1214 	if (!res)
1215 		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1216 
1217 	master = p->master;
1218 	master->dma_tx = sh_msiof_request_dma_chan(dev, DMA_MEM_TO_DEV,
1219 						   dma_tx_id,
1220 						   res->start + TFDR);
1221 	if (!master->dma_tx)
1222 		return -ENODEV;
1223 
1224 	master->dma_rx = sh_msiof_request_dma_chan(dev, DMA_DEV_TO_MEM,
1225 						   dma_rx_id,
1226 						   res->start + RFDR);
1227 	if (!master->dma_rx)
1228 		goto free_tx_chan;
1229 
1230 	p->tx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
1231 	if (!p->tx_dma_page)
1232 		goto free_rx_chan;
1233 
1234 	p->rx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
1235 	if (!p->rx_dma_page)
1236 		goto free_tx_page;
1237 
1238 	tx_dev = master->dma_tx->device->dev;
1239 	p->tx_dma_addr = dma_map_single(tx_dev, p->tx_dma_page, PAGE_SIZE,
1240 					DMA_TO_DEVICE);
1241 	if (dma_mapping_error(tx_dev, p->tx_dma_addr))
1242 		goto free_rx_page;
1243 
1244 	rx_dev = master->dma_rx->device->dev;
1245 	p->rx_dma_addr = dma_map_single(rx_dev, p->rx_dma_page, PAGE_SIZE,
1246 					DMA_FROM_DEVICE);
1247 	if (dma_mapping_error(rx_dev, p->rx_dma_addr))
1248 		goto unmap_tx_page;
1249 
1250 	dev_info(dev, "DMA available");
1251 	return 0;
1252 
1253 unmap_tx_page:
1254 	dma_unmap_single(tx_dev, p->tx_dma_addr, PAGE_SIZE, DMA_TO_DEVICE);
1255 free_rx_page:
1256 	free_page((unsigned long)p->rx_dma_page);
1257 free_tx_page:
1258 	free_page((unsigned long)p->tx_dma_page);
1259 free_rx_chan:
1260 	dma_release_channel(master->dma_rx);
1261 free_tx_chan:
1262 	dma_release_channel(master->dma_tx);
1263 	master->dma_tx = NULL;
1264 	return -ENODEV;
1265 }
1266 
1267 static void sh_msiof_release_dma(struct sh_msiof_spi_priv *p)
1268 {
1269 	struct spi_master *master = p->master;
1270 
1271 	if (!master->dma_tx)
1272 		return;
1273 
1274 	dma_unmap_single(master->dma_rx->device->dev, p->rx_dma_addr,
1275 			 PAGE_SIZE, DMA_FROM_DEVICE);
1276 	dma_unmap_single(master->dma_tx->device->dev, p->tx_dma_addr,
1277 			 PAGE_SIZE, DMA_TO_DEVICE);
1278 	free_page((unsigned long)p->rx_dma_page);
1279 	free_page((unsigned long)p->tx_dma_page);
1280 	dma_release_channel(master->dma_rx);
1281 	dma_release_channel(master->dma_tx);
1282 }
1283 
1284 static int sh_msiof_spi_probe(struct platform_device *pdev)
1285 {
1286 	struct resource	*r;
1287 	struct spi_master *master;
1288 	const struct sh_msiof_chipdata *chipdata;
1289 	struct sh_msiof_spi_info *info;
1290 	struct sh_msiof_spi_priv *p;
1291 	int i;
1292 	int ret;
1293 
1294 	chipdata = of_device_get_match_data(&pdev->dev);
1295 	if (chipdata) {
1296 		info = sh_msiof_spi_parse_dt(&pdev->dev);
1297 	} else {
1298 		chipdata = (const void *)pdev->id_entry->driver_data;
1299 		info = dev_get_platdata(&pdev->dev);
1300 	}
1301 
1302 	if (!info) {
1303 		dev_err(&pdev->dev, "failed to obtain device info\n");
1304 		return -ENXIO;
1305 	}
1306 
1307 	if (info->mode == MSIOF_SPI_SLAVE)
1308 		master = spi_alloc_slave(&pdev->dev,
1309 					 sizeof(struct sh_msiof_spi_priv));
1310 	else
1311 		master = spi_alloc_master(&pdev->dev,
1312 					  sizeof(struct sh_msiof_spi_priv));
1313 	if (master == NULL)
1314 		return -ENOMEM;
1315 
1316 	p = spi_master_get_devdata(master);
1317 
1318 	platform_set_drvdata(pdev, p);
1319 	p->master = master;
1320 	p->info = info;
1321 	p->min_div = chipdata->min_div;
1322 
1323 	init_completion(&p->done);
1324 
1325 	p->clk = devm_clk_get(&pdev->dev, NULL);
1326 	if (IS_ERR(p->clk)) {
1327 		dev_err(&pdev->dev, "cannot get clock\n");
1328 		ret = PTR_ERR(p->clk);
1329 		goto err1;
1330 	}
1331 
1332 	i = platform_get_irq(pdev, 0);
1333 	if (i < 0) {
1334 		dev_err(&pdev->dev, "cannot get platform IRQ\n");
1335 		ret = -ENOENT;
1336 		goto err1;
1337 	}
1338 
1339 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1340 	p->mapbase = devm_ioremap_resource(&pdev->dev, r);
1341 	if (IS_ERR(p->mapbase)) {
1342 		ret = PTR_ERR(p->mapbase);
1343 		goto err1;
1344 	}
1345 
1346 	ret = devm_request_irq(&pdev->dev, i, sh_msiof_spi_irq, 0,
1347 			       dev_name(&pdev->dev), p);
1348 	if (ret) {
1349 		dev_err(&pdev->dev, "unable to request irq\n");
1350 		goto err1;
1351 	}
1352 
1353 	p->pdev = pdev;
1354 	pm_runtime_enable(&pdev->dev);
1355 
1356 	/* Platform data may override FIFO sizes */
1357 	p->tx_fifo_size = chipdata->tx_fifo_size;
1358 	p->rx_fifo_size = chipdata->rx_fifo_size;
1359 	if (p->info->tx_fifo_override)
1360 		p->tx_fifo_size = p->info->tx_fifo_override;
1361 	if (p->info->rx_fifo_override)
1362 		p->rx_fifo_size = p->info->rx_fifo_override;
1363 
1364 	/* Setup GPIO chip selects */
1365 	master->num_chipselect = p->info->num_chipselect;
1366 	ret = sh_msiof_get_cs_gpios(p);
1367 	if (ret)
1368 		goto err1;
1369 
1370 	/* init master code */
1371 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1372 	master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
1373 	master->flags = chipdata->master_flags;
1374 	master->bus_num = pdev->id;
1375 	master->dev.of_node = pdev->dev.of_node;
1376 	master->setup = sh_msiof_spi_setup;
1377 	master->prepare_message = sh_msiof_prepare_message;
1378 	master->slave_abort = sh_msiof_slave_abort;
1379 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32);
1380 	master->auto_runtime_pm = true;
1381 	master->transfer_one = sh_msiof_transfer_one;
1382 
1383 	ret = sh_msiof_request_dma(p);
1384 	if (ret < 0)
1385 		dev_warn(&pdev->dev, "DMA not available, using PIO\n");
1386 
1387 	ret = devm_spi_register_master(&pdev->dev, master);
1388 	if (ret < 0) {
1389 		dev_err(&pdev->dev, "spi_register_master error.\n");
1390 		goto err2;
1391 	}
1392 
1393 	return 0;
1394 
1395  err2:
1396 	sh_msiof_release_dma(p);
1397 	pm_runtime_disable(&pdev->dev);
1398  err1:
1399 	spi_master_put(master);
1400 	return ret;
1401 }
1402 
1403 static int sh_msiof_spi_remove(struct platform_device *pdev)
1404 {
1405 	struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
1406 
1407 	sh_msiof_release_dma(p);
1408 	pm_runtime_disable(&pdev->dev);
1409 	return 0;
1410 }
1411 
1412 static const struct platform_device_id spi_driver_ids[] = {
1413 	{ "spi_sh_msiof",	(kernel_ulong_t)&sh_data },
1414 	{},
1415 };
1416 MODULE_DEVICE_TABLE(platform, spi_driver_ids);
1417 
1418 static struct platform_driver sh_msiof_spi_drv = {
1419 	.probe		= sh_msiof_spi_probe,
1420 	.remove		= sh_msiof_spi_remove,
1421 	.id_table	= spi_driver_ids,
1422 	.driver		= {
1423 		.name		= "spi_sh_msiof",
1424 		.of_match_table = of_match_ptr(sh_msiof_match),
1425 	},
1426 };
1427 module_platform_driver(sh_msiof_spi_drv);
1428 
1429 MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
1430 MODULE_AUTHOR("Magnus Damm");
1431 MODULE_LICENSE("GPL v2");
1432 MODULE_ALIAS("platform:spi_sh_msiof");
1433