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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 	const struct sh_msiof_chipdata *chipdata;
49 	struct sh_msiof_spi_info *info;
50 	struct completion done;
51 	unsigned int tx_fifo_size;
52 	unsigned int rx_fifo_size;
53 	void *tx_dma_page;
54 	void *rx_dma_page;
55 	dma_addr_t tx_dma_addr;
56 	dma_addr_t rx_dma_addr;
57 };
58 
59 #define TMDR1	0x00	/* Transmit Mode Register 1 */
60 #define TMDR2	0x04	/* Transmit Mode Register 2 */
61 #define TMDR3	0x08	/* Transmit Mode Register 3 */
62 #define RMDR1	0x10	/* Receive Mode Register 1 */
63 #define RMDR2	0x14	/* Receive Mode Register 2 */
64 #define RMDR3	0x18	/* Receive Mode Register 3 */
65 #define TSCR	0x20	/* Transmit Clock Select Register */
66 #define RSCR	0x22	/* Receive Clock Select Register (SH, A1, APE6) */
67 #define CTR	0x28	/* Control Register */
68 #define FCTR	0x30	/* FIFO Control Register */
69 #define STR	0x40	/* Status Register */
70 #define IER	0x44	/* Interrupt Enable Register */
71 #define TDR1	0x48	/* Transmit Control Data Register 1 (SH, A1) */
72 #define TDR2	0x4c	/* Transmit Control Data Register 2 (SH, A1) */
73 #define TFDR	0x50	/* Transmit FIFO Data Register */
74 #define RDR1	0x58	/* Receive Control Data Register 1 (SH, A1) */
75 #define RDR2	0x5c	/* Receive Control Data Register 2 (SH, A1) */
76 #define RFDR	0x60	/* Receive FIFO Data Register */
77 
78 /* TMDR1 and RMDR1 */
79 #define MDR1_TRMD	 0x80000000 /* Transfer Mode (1 = Master mode) */
80 #define MDR1_SYNCMD_MASK 0x30000000 /* SYNC Mode */
81 #define MDR1_SYNCMD_SPI	 0x20000000 /*   Level mode/SPI */
82 #define MDR1_SYNCMD_LR	 0x30000000 /*   L/R mode */
83 #define MDR1_SYNCAC_SHIFT	 25 /* Sync Polarity (1 = Active-low) */
84 #define MDR1_BITLSB_SHIFT	 24 /* MSB/LSB First (1 = LSB first) */
85 #define MDR1_DTDL_SHIFT		 20 /* Data Pin Bit Delay for MSIOF_SYNC */
86 #define MDR1_SYNCDL_SHIFT	 16 /* Frame Sync Signal Timing Delay */
87 #define MDR1_FLD_MASK	 0x0000000c /* Frame Sync Signal Interval (0-3) */
88 #define MDR1_FLD_SHIFT		  2
89 #define MDR1_XXSTP	 0x00000001 /* Transmission/Reception Stop on FIFO */
90 /* TMDR1 */
91 #define TMDR1_PCON	 0x40000000 /* Transfer Signal Connection */
92 
93 /* TMDR2 and RMDR2 */
94 #define MDR2_BITLEN1(i)	(((i) - 1) << 24) /* Data Size (8-32 bits) */
95 #define MDR2_WDLEN1(i)	(((i) - 1) << 16) /* Word Count (1-64/256 (SH, A1))) */
96 #define MDR2_GRPMASK1	0x00000001 /* Group Output Mask 1 (SH, A1) */
97 
98 /* TSCR and RSCR */
99 #define SCR_BRPS_MASK	    0x1f00 /* Prescaler Setting (1-32) */
100 #define SCR_BRPS(i)	(((i) - 1) << 8)
101 #define SCR_BRDV_MASK	    0x0007 /* Baud Rate Generator's Division Ratio */
102 #define SCR_BRDV_DIV_2	    0x0000
103 #define SCR_BRDV_DIV_4	    0x0001
104 #define SCR_BRDV_DIV_8	    0x0002
105 #define SCR_BRDV_DIV_16	    0x0003
106 #define SCR_BRDV_DIV_32	    0x0004
107 #define SCR_BRDV_DIV_1	    0x0007
108 
109 /* CTR */
110 #define CTR_TSCKIZ_MASK	0xc0000000 /* Transmit Clock I/O Polarity Select */
111 #define CTR_TSCKIZ_SCK	0x80000000 /*   Disable SCK when TX disabled */
112 #define CTR_TSCKIZ_POL_SHIFT	30 /*   Transmit Clock Polarity */
113 #define CTR_RSCKIZ_MASK	0x30000000 /* Receive Clock Polarity Select */
114 #define CTR_RSCKIZ_SCK	0x20000000 /*   Must match CTR_TSCKIZ_SCK */
115 #define CTR_RSCKIZ_POL_SHIFT	28 /*   Receive Clock Polarity */
116 #define CTR_TEDG_SHIFT		27 /* Transmit Timing (1 = falling edge) */
117 #define CTR_REDG_SHIFT		26 /* Receive Timing (1 = falling edge) */
118 #define CTR_TXDIZ_MASK	0x00c00000 /* Pin Output When TX is Disabled */
119 #define CTR_TXDIZ_LOW	0x00000000 /*   0 */
120 #define CTR_TXDIZ_HIGH	0x00400000 /*   1 */
121 #define CTR_TXDIZ_HIZ	0x00800000 /*   High-impedance */
122 #define CTR_TSCKE	0x00008000 /* Transmit Serial Clock Output Enable */
123 #define CTR_TFSE	0x00004000 /* Transmit Frame Sync Signal Output Enable */
124 #define CTR_TXE		0x00000200 /* Transmit Enable */
125 #define CTR_RXE		0x00000100 /* Receive Enable */
126 
127 /* FCTR */
128 #define FCTR_TFWM_MASK	0xe0000000 /* Transmit FIFO Watermark */
129 #define FCTR_TFWM_64	0x00000000 /*  Transfer Request when 64 empty stages */
130 #define FCTR_TFWM_32	0x20000000 /*  Transfer Request when 32 empty stages */
131 #define FCTR_TFWM_24	0x40000000 /*  Transfer Request when 24 empty stages */
132 #define FCTR_TFWM_16	0x60000000 /*  Transfer Request when 16 empty stages */
133 #define FCTR_TFWM_12	0x80000000 /*  Transfer Request when 12 empty stages */
134 #define FCTR_TFWM_8	0xa0000000 /*  Transfer Request when 8 empty stages */
135 #define FCTR_TFWM_4	0xc0000000 /*  Transfer Request when 4 empty stages */
136 #define FCTR_TFWM_1	0xe0000000 /*  Transfer Request when 1 empty stage */
137 #define FCTR_TFUA_MASK	0x07f00000 /* Transmit FIFO Usable Area */
138 #define FCTR_TFUA_SHIFT		20
139 #define FCTR_TFUA(i)	((i) << FCTR_TFUA_SHIFT)
140 #define FCTR_RFWM_MASK	0x0000e000 /* Receive FIFO Watermark */
141 #define FCTR_RFWM_1	0x00000000 /*  Transfer Request when 1 valid stages */
142 #define FCTR_RFWM_4	0x00002000 /*  Transfer Request when 4 valid stages */
143 #define FCTR_RFWM_8	0x00004000 /*  Transfer Request when 8 valid stages */
144 #define FCTR_RFWM_16	0x00006000 /*  Transfer Request when 16 valid stages */
145 #define FCTR_RFWM_32	0x00008000 /*  Transfer Request when 32 valid stages */
146 #define FCTR_RFWM_64	0x0000a000 /*  Transfer Request when 64 valid stages */
147 #define FCTR_RFWM_128	0x0000c000 /*  Transfer Request when 128 valid stages */
148 #define FCTR_RFWM_256	0x0000e000 /*  Transfer Request when 256 valid stages */
149 #define FCTR_RFUA_MASK	0x00001ff0 /* Receive FIFO Usable Area (0x40 = full) */
150 #define FCTR_RFUA_SHIFT		 4
151 #define FCTR_RFUA(i)	((i) << FCTR_RFUA_SHIFT)
152 
153 /* STR */
154 #define STR_TFEMP	0x20000000 /* Transmit FIFO Empty */
155 #define STR_TDREQ	0x10000000 /* Transmit Data Transfer Request */
156 #define STR_TEOF	0x00800000 /* Frame Transmission End */
157 #define STR_TFSERR	0x00200000 /* Transmit Frame Synchronization Error */
158 #define STR_TFOVF	0x00100000 /* Transmit FIFO Overflow */
159 #define STR_TFUDF	0x00080000 /* Transmit FIFO Underflow */
160 #define STR_RFFUL	0x00002000 /* Receive FIFO Full */
161 #define STR_RDREQ	0x00001000 /* Receive Data Transfer Request */
162 #define STR_REOF	0x00000080 /* Frame Reception End */
163 #define STR_RFSERR	0x00000020 /* Receive Frame Synchronization Error */
164 #define STR_RFUDF	0x00000010 /* Receive FIFO Underflow */
165 #define STR_RFOVF	0x00000008 /* Receive FIFO Overflow */
166 
167 /* IER */
168 #define IER_TDMAE	0x80000000 /* Transmit Data DMA Transfer Req. Enable */
169 #define IER_TFEMPE	0x20000000 /* Transmit FIFO Empty Enable */
170 #define IER_TDREQE	0x10000000 /* Transmit Data Transfer Request Enable */
171 #define IER_TEOFE	0x00800000 /* Frame Transmission End Enable */
172 #define IER_TFSERRE	0x00200000 /* Transmit Frame Sync Error Enable */
173 #define IER_TFOVFE	0x00100000 /* Transmit FIFO Overflow Enable */
174 #define IER_TFUDFE	0x00080000 /* Transmit FIFO Underflow Enable */
175 #define IER_RDMAE	0x00008000 /* Receive Data DMA Transfer Req. Enable */
176 #define IER_RFFULE	0x00002000 /* Receive FIFO Full Enable */
177 #define IER_RDREQE	0x00001000 /* Receive Data Transfer Request Enable */
178 #define IER_REOFE	0x00000080 /* Frame Reception End Enable */
179 #define IER_RFSERRE	0x00000020 /* Receive Frame Sync Error Enable */
180 #define IER_RFUDFE	0x00000010 /* Receive FIFO Underflow Enable */
181 #define IER_RFOVFE	0x00000008 /* Receive FIFO Overflow Enable */
182 
183 
sh_msiof_read(struct sh_msiof_spi_priv * p,int reg_offs)184 static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs)
185 {
186 	switch (reg_offs) {
187 	case TSCR:
188 	case RSCR:
189 		return ioread16(p->mapbase + reg_offs);
190 	default:
191 		return ioread32(p->mapbase + reg_offs);
192 	}
193 }
194 
sh_msiof_write(struct sh_msiof_spi_priv * p,int reg_offs,u32 value)195 static void sh_msiof_write(struct sh_msiof_spi_priv *p, int reg_offs,
196 			   u32 value)
197 {
198 	switch (reg_offs) {
199 	case TSCR:
200 	case RSCR:
201 		iowrite16(value, p->mapbase + reg_offs);
202 		break;
203 	default:
204 		iowrite32(value, p->mapbase + reg_offs);
205 		break;
206 	}
207 }
208 
sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv * p,u32 clr,u32 set)209 static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv *p,
210 				    u32 clr, u32 set)
211 {
212 	u32 mask = clr | set;
213 	u32 data;
214 	int k;
215 
216 	data = sh_msiof_read(p, CTR);
217 	data &= ~clr;
218 	data |= set;
219 	sh_msiof_write(p, CTR, data);
220 
221 	for (k = 100; k > 0; k--) {
222 		if ((sh_msiof_read(p, CTR) & mask) == set)
223 			break;
224 
225 		udelay(10);
226 	}
227 
228 	return k > 0 ? 0 : -ETIMEDOUT;
229 }
230 
sh_msiof_spi_irq(int irq,void * data)231 static irqreturn_t sh_msiof_spi_irq(int irq, void *data)
232 {
233 	struct sh_msiof_spi_priv *p = data;
234 
235 	/* just disable the interrupt and wake up */
236 	sh_msiof_write(p, IER, 0);
237 	complete(&p->done);
238 
239 	return IRQ_HANDLED;
240 }
241 
242 static struct {
243 	unsigned short div;
244 	unsigned short brdv;
245 } const sh_msiof_spi_div_table[] = {
246 	{ 1,	SCR_BRDV_DIV_1 },
247 	{ 2,	SCR_BRDV_DIV_2 },
248 	{ 4,	SCR_BRDV_DIV_4 },
249 	{ 8,	SCR_BRDV_DIV_8 },
250 	{ 16,	SCR_BRDV_DIV_16 },
251 	{ 32,	SCR_BRDV_DIV_32 },
252 };
253 
sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv * p,unsigned long parent_rate,u32 spi_hz)254 static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
255 				      unsigned long parent_rate, u32 spi_hz)
256 {
257 	unsigned long div = 1024;
258 	u32 brps, scr;
259 	size_t k;
260 
261 	if (!WARN_ON(!spi_hz || !parent_rate))
262 		div = DIV_ROUND_UP(parent_rate, spi_hz);
263 
264 	for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_div_table); k++) {
265 		brps = DIV_ROUND_UP(div, sh_msiof_spi_div_table[k].div);
266 		/* SCR_BRDV_DIV_1 is valid only if BRPS is x 1/1 or x 1/2 */
267 		if (sh_msiof_spi_div_table[k].div == 1 && brps > 2)
268 			continue;
269 		if (brps <= 32) /* max of brdv is 32 */
270 			break;
271 	}
272 
273 	k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_div_table) - 1);
274 
275 	scr = sh_msiof_spi_div_table[k].brdv | SCR_BRPS(brps);
276 	sh_msiof_write(p, TSCR, scr);
277 	if (!(p->chipdata->master_flags & SPI_MASTER_MUST_TX))
278 		sh_msiof_write(p, RSCR, scr);
279 }
280 
sh_msiof_get_delay_bit(u32 dtdl_or_syncdl)281 static u32 sh_msiof_get_delay_bit(u32 dtdl_or_syncdl)
282 {
283 	/*
284 	 * DTDL/SYNCDL bit	: p->info->dtdl or p->info->syncdl
285 	 * b'000		: 0
286 	 * b'001		: 100
287 	 * b'010		: 200
288 	 * b'011 (SYNCDL only)	: 300
289 	 * b'101		: 50
290 	 * b'110		: 150
291 	 */
292 	if (dtdl_or_syncdl % 100)
293 		return dtdl_or_syncdl / 100 + 5;
294 	else
295 		return dtdl_or_syncdl / 100;
296 }
297 
sh_msiof_spi_get_dtdl_and_syncdl(struct sh_msiof_spi_priv * p)298 static u32 sh_msiof_spi_get_dtdl_and_syncdl(struct sh_msiof_spi_priv *p)
299 {
300 	u32 val;
301 
302 	if (!p->info)
303 		return 0;
304 
305 	/* check if DTDL and SYNCDL is allowed value */
306 	if (p->info->dtdl > 200 || p->info->syncdl > 300) {
307 		dev_warn(&p->pdev->dev, "DTDL or SYNCDL is too large\n");
308 		return 0;
309 	}
310 
311 	/* check if the sum of DTDL and SYNCDL becomes an integer value  */
312 	if ((p->info->dtdl + p->info->syncdl) % 100) {
313 		dev_warn(&p->pdev->dev, "the sum of DTDL/SYNCDL is not good\n");
314 		return 0;
315 	}
316 
317 	val = sh_msiof_get_delay_bit(p->info->dtdl) << MDR1_DTDL_SHIFT;
318 	val |= sh_msiof_get_delay_bit(p->info->syncdl) << MDR1_SYNCDL_SHIFT;
319 
320 	return val;
321 }
322 
sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv * p,u32 cpol,u32 cpha,u32 tx_hi_z,u32 lsb_first,u32 cs_high)323 static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
324 				      u32 cpol, u32 cpha,
325 				      u32 tx_hi_z, u32 lsb_first, u32 cs_high)
326 {
327 	u32 tmp;
328 	int edge;
329 
330 	/*
331 	 * CPOL CPHA     TSCKIZ RSCKIZ TEDG REDG
332 	 *    0    0         10     10    1    1
333 	 *    0    1         10     10    0    0
334 	 *    1    0         11     11    0    0
335 	 *    1    1         11     11    1    1
336 	 */
337 	tmp = MDR1_SYNCMD_SPI | 1 << MDR1_FLD_SHIFT | MDR1_XXSTP;
338 	tmp |= !cs_high << MDR1_SYNCAC_SHIFT;
339 	tmp |= lsb_first << MDR1_BITLSB_SHIFT;
340 	tmp |= sh_msiof_spi_get_dtdl_and_syncdl(p);
341 	sh_msiof_write(p, TMDR1, tmp | MDR1_TRMD | TMDR1_PCON);
342 	if (p->chipdata->master_flags & SPI_MASTER_MUST_TX) {
343 		/* These bits are reserved if RX needs TX */
344 		tmp &= ~0x0000ffff;
345 	}
346 	sh_msiof_write(p, RMDR1, tmp);
347 
348 	tmp = 0;
349 	tmp |= CTR_TSCKIZ_SCK | cpol << CTR_TSCKIZ_POL_SHIFT;
350 	tmp |= CTR_RSCKIZ_SCK | cpol << CTR_RSCKIZ_POL_SHIFT;
351 
352 	edge = cpol ^ !cpha;
353 
354 	tmp |= edge << CTR_TEDG_SHIFT;
355 	tmp |= edge << CTR_REDG_SHIFT;
356 	tmp |= tx_hi_z ? CTR_TXDIZ_HIZ : CTR_TXDIZ_LOW;
357 	sh_msiof_write(p, CTR, tmp);
358 }
359 
sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv * p,const void * tx_buf,void * rx_buf,u32 bits,u32 words)360 static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
361 				       const void *tx_buf, void *rx_buf,
362 				       u32 bits, u32 words)
363 {
364 	u32 dr2 = MDR2_BITLEN1(bits) | MDR2_WDLEN1(words);
365 
366 	if (tx_buf || (p->chipdata->master_flags & SPI_MASTER_MUST_TX))
367 		sh_msiof_write(p, TMDR2, dr2);
368 	else
369 		sh_msiof_write(p, TMDR2, dr2 | MDR2_GRPMASK1);
370 
371 	if (rx_buf)
372 		sh_msiof_write(p, RMDR2, dr2);
373 }
374 
sh_msiof_reset_str(struct sh_msiof_spi_priv * p)375 static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
376 {
377 	sh_msiof_write(p, STR,
378 		       sh_msiof_read(p, STR) & ~(STR_TDREQ | STR_RDREQ));
379 }
380 
sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv * p,const void * tx_buf,int words,int fs)381 static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
382 				      const void *tx_buf, int words, int fs)
383 {
384 	const u8 *buf_8 = tx_buf;
385 	int k;
386 
387 	for (k = 0; k < words; k++)
388 		sh_msiof_write(p, TFDR, buf_8[k] << fs);
389 }
390 
sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv * p,const void * tx_buf,int words,int fs)391 static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
392 				       const void *tx_buf, int words, int fs)
393 {
394 	const u16 *buf_16 = tx_buf;
395 	int k;
396 
397 	for (k = 0; k < words; k++)
398 		sh_msiof_write(p, TFDR, buf_16[k] << fs);
399 }
400 
sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv * p,const void * tx_buf,int words,int fs)401 static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
402 					const void *tx_buf, int words, int fs)
403 {
404 	const u16 *buf_16 = tx_buf;
405 	int k;
406 
407 	for (k = 0; k < words; k++)
408 		sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
409 }
410 
sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv * p,const void * tx_buf,int words,int fs)411 static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
412 				       const void *tx_buf, int words, int fs)
413 {
414 	const u32 *buf_32 = tx_buf;
415 	int k;
416 
417 	for (k = 0; k < words; k++)
418 		sh_msiof_write(p, TFDR, buf_32[k] << fs);
419 }
420 
sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv * p,const void * tx_buf,int words,int fs)421 static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
422 					const void *tx_buf, int words, int fs)
423 {
424 	const u32 *buf_32 = tx_buf;
425 	int k;
426 
427 	for (k = 0; k < words; k++)
428 		sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
429 }
430 
sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv * p,const void * tx_buf,int words,int fs)431 static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
432 					const void *tx_buf, int words, int fs)
433 {
434 	const u32 *buf_32 = tx_buf;
435 	int k;
436 
437 	for (k = 0; k < words; k++)
438 		sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
439 }
440 
sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv * p,const void * tx_buf,int words,int fs)441 static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
442 					 const void *tx_buf, int words, int fs)
443 {
444 	const u32 *buf_32 = tx_buf;
445 	int k;
446 
447 	for (k = 0; k < words; k++)
448 		sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
449 }
450 
sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv * p,void * rx_buf,int words,int fs)451 static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
452 				     void *rx_buf, int words, int fs)
453 {
454 	u8 *buf_8 = rx_buf;
455 	int k;
456 
457 	for (k = 0; k < words; k++)
458 		buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
459 }
460 
sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv * p,void * rx_buf,int words,int fs)461 static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
462 				      void *rx_buf, int words, int fs)
463 {
464 	u16 *buf_16 = rx_buf;
465 	int k;
466 
467 	for (k = 0; k < words; k++)
468 		buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
469 }
470 
sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv * p,void * rx_buf,int words,int fs)471 static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
472 				       void *rx_buf, int words, int fs)
473 {
474 	u16 *buf_16 = rx_buf;
475 	int k;
476 
477 	for (k = 0; k < words; k++)
478 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
479 }
480 
sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv * p,void * rx_buf,int words,int fs)481 static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
482 				      void *rx_buf, int words, int fs)
483 {
484 	u32 *buf_32 = rx_buf;
485 	int k;
486 
487 	for (k = 0; k < words; k++)
488 		buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
489 }
490 
sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv * p,void * rx_buf,int words,int fs)491 static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
492 				       void *rx_buf, int words, int fs)
493 {
494 	u32 *buf_32 = rx_buf;
495 	int k;
496 
497 	for (k = 0; k < words; k++)
498 		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
499 }
500 
sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv * p,void * rx_buf,int words,int fs)501 static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
502 				       void *rx_buf, int words, int fs)
503 {
504 	u32 *buf_32 = rx_buf;
505 	int k;
506 
507 	for (k = 0; k < words; k++)
508 		buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
509 }
510 
sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv * p,void * rx_buf,int words,int fs)511 static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
512 				       void *rx_buf, int words, int fs)
513 {
514 	u32 *buf_32 = rx_buf;
515 	int k;
516 
517 	for (k = 0; k < words; k++)
518 		put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
519 }
520 
sh_msiof_spi_setup(struct spi_device * spi)521 static int sh_msiof_spi_setup(struct spi_device *spi)
522 {
523 	struct device_node	*np = spi->master->dev.of_node;
524 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
525 
526 	pm_runtime_get_sync(&p->pdev->dev);
527 
528 	if (!np) {
529 		/*
530 		 * Use spi->controller_data for CS (same strategy as spi_gpio),
531 		 * if any. otherwise let HW control CS
532 		 */
533 		spi->cs_gpio = (uintptr_t)spi->controller_data;
534 	}
535 
536 	/* Configure pins before deasserting CS */
537 	sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
538 				  !!(spi->mode & SPI_CPHA),
539 				  !!(spi->mode & SPI_3WIRE),
540 				  !!(spi->mode & SPI_LSB_FIRST),
541 				  !!(spi->mode & SPI_CS_HIGH));
542 
543 	if (spi->cs_gpio >= 0)
544 		gpio_set_value(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
545 
546 
547 	pm_runtime_put(&p->pdev->dev);
548 
549 	return 0;
550 }
551 
sh_msiof_prepare_message(struct spi_master * master,struct spi_message * msg)552 static int sh_msiof_prepare_message(struct spi_master *master,
553 				    struct spi_message *msg)
554 {
555 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
556 	const struct spi_device *spi = msg->spi;
557 
558 	/* Configure pins before asserting CS */
559 	sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
560 				  !!(spi->mode & SPI_CPHA),
561 				  !!(spi->mode & SPI_3WIRE),
562 				  !!(spi->mode & SPI_LSB_FIRST),
563 				  !!(spi->mode & SPI_CS_HIGH));
564 	return 0;
565 }
566 
sh_msiof_spi_start(struct sh_msiof_spi_priv * p,void * rx_buf)567 static int sh_msiof_spi_start(struct sh_msiof_spi_priv *p, void *rx_buf)
568 {
569 	int ret;
570 
571 	/* setup clock and rx/tx signals */
572 	ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
573 	if (rx_buf && !ret)
574 		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
575 	if (!ret)
576 		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);
577 
578 	/* start by setting frame bit */
579 	if (!ret)
580 		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
581 
582 	return ret;
583 }
584 
sh_msiof_spi_stop(struct sh_msiof_spi_priv * p,void * rx_buf)585 static int sh_msiof_spi_stop(struct sh_msiof_spi_priv *p, void *rx_buf)
586 {
587 	int ret;
588 
589 	/* shut down frame, rx/tx and clock signals */
590 	ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
591 	if (!ret)
592 		ret = sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
593 	if (rx_buf && !ret)
594 		ret = sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
595 	if (!ret)
596 		ret = sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
597 
598 	return ret;
599 }
600 
sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv * p,void (* tx_fifo)(struct sh_msiof_spi_priv *,const void *,int,int),void (* rx_fifo)(struct sh_msiof_spi_priv *,void *,int,int),const void * tx_buf,void * rx_buf,int words,int bits)601 static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
602 				  void (*tx_fifo)(struct sh_msiof_spi_priv *,
603 						  const void *, int, int),
604 				  void (*rx_fifo)(struct sh_msiof_spi_priv *,
605 						  void *, int, int),
606 				  const void *tx_buf, void *rx_buf,
607 				  int words, int bits)
608 {
609 	int fifo_shift;
610 	int ret;
611 
612 	/* limit maximum word transfer to rx/tx fifo size */
613 	if (tx_buf)
614 		words = min_t(int, words, p->tx_fifo_size);
615 	if (rx_buf)
616 		words = min_t(int, words, p->rx_fifo_size);
617 
618 	/* the fifo contents need shifting */
619 	fifo_shift = 32 - bits;
620 
621 	/* default FIFO watermarks for PIO */
622 	sh_msiof_write(p, FCTR, 0);
623 
624 	/* setup msiof transfer mode registers */
625 	sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);
626 	sh_msiof_write(p, IER, IER_TEOFE | IER_REOFE);
627 
628 	/* write tx fifo */
629 	if (tx_buf)
630 		tx_fifo(p, tx_buf, words, fifo_shift);
631 
632 	reinit_completion(&p->done);
633 
634 	ret = sh_msiof_spi_start(p, rx_buf);
635 	if (ret) {
636 		dev_err(&p->pdev->dev, "failed to start hardware\n");
637 		goto stop_ier;
638 	}
639 
640 	/* wait for tx fifo to be emptied / rx fifo to be filled */
641 	if (!wait_for_completion_timeout(&p->done, HZ)) {
642 		dev_err(&p->pdev->dev, "PIO timeout\n");
643 		ret = -ETIMEDOUT;
644 		goto stop_reset;
645 	}
646 
647 	/* read rx fifo */
648 	if (rx_buf)
649 		rx_fifo(p, rx_buf, words, fifo_shift);
650 
651 	/* clear status bits */
652 	sh_msiof_reset_str(p);
653 
654 	ret = sh_msiof_spi_stop(p, rx_buf);
655 	if (ret) {
656 		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
657 		return ret;
658 	}
659 
660 	return words;
661 
662 stop_reset:
663 	sh_msiof_reset_str(p);
664 	sh_msiof_spi_stop(p, rx_buf);
665 stop_ier:
666 	sh_msiof_write(p, IER, 0);
667 	return ret;
668 }
669 
sh_msiof_dma_complete(void * arg)670 static void sh_msiof_dma_complete(void *arg)
671 {
672 	struct sh_msiof_spi_priv *p = arg;
673 
674 	sh_msiof_write(p, IER, 0);
675 	complete(&p->done);
676 }
677 
sh_msiof_dma_once(struct sh_msiof_spi_priv * p,const void * tx,void * rx,unsigned int len)678 static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
679 			     void *rx, unsigned int len)
680 {
681 	u32 ier_bits = 0;
682 	struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
683 	dma_cookie_t cookie;
684 	int ret;
685 
686 	/* First prepare and submit the DMA request(s), as this may fail */
687 	if (rx) {
688 		ier_bits |= IER_RDREQE | IER_RDMAE;
689 		desc_rx = dmaengine_prep_slave_single(p->master->dma_rx,
690 					p->rx_dma_addr, len, DMA_FROM_DEVICE,
691 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
692 		if (!desc_rx)
693 			return -EAGAIN;
694 
695 		desc_rx->callback = sh_msiof_dma_complete;
696 		desc_rx->callback_param = p;
697 		cookie = dmaengine_submit(desc_rx);
698 		if (dma_submit_error(cookie))
699 			return cookie;
700 	}
701 
702 	if (tx) {
703 		ier_bits |= IER_TDREQE | IER_TDMAE;
704 		dma_sync_single_for_device(p->master->dma_tx->device->dev,
705 					   p->tx_dma_addr, len, DMA_TO_DEVICE);
706 		desc_tx = dmaengine_prep_slave_single(p->master->dma_tx,
707 					p->tx_dma_addr, len, DMA_TO_DEVICE,
708 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
709 		if (!desc_tx) {
710 			ret = -EAGAIN;
711 			goto no_dma_tx;
712 		}
713 
714 		if (rx) {
715 			/* No callback */
716 			desc_tx->callback = NULL;
717 		} else {
718 			desc_tx->callback = sh_msiof_dma_complete;
719 			desc_tx->callback_param = p;
720 		}
721 		cookie = dmaengine_submit(desc_tx);
722 		if (dma_submit_error(cookie)) {
723 			ret = cookie;
724 			goto no_dma_tx;
725 		}
726 	}
727 
728 	/* 1 stage FIFO watermarks for DMA */
729 	sh_msiof_write(p, FCTR, FCTR_TFWM_1 | FCTR_RFWM_1);
730 
731 	/* setup msiof transfer mode registers (32-bit words) */
732 	sh_msiof_spi_set_mode_regs(p, tx, rx, 32, len / 4);
733 
734 	sh_msiof_write(p, IER, ier_bits);
735 
736 	reinit_completion(&p->done);
737 
738 	/* Now start DMA */
739 	if (rx)
740 		dma_async_issue_pending(p->master->dma_rx);
741 	if (tx)
742 		dma_async_issue_pending(p->master->dma_tx);
743 
744 	ret = sh_msiof_spi_start(p, rx);
745 	if (ret) {
746 		dev_err(&p->pdev->dev, "failed to start hardware\n");
747 		goto stop_dma;
748 	}
749 
750 	/* wait for tx fifo to be emptied / rx fifo to be filled */
751 	if (!wait_for_completion_timeout(&p->done, HZ)) {
752 		dev_err(&p->pdev->dev, "DMA timeout\n");
753 		ret = -ETIMEDOUT;
754 		goto stop_reset;
755 	}
756 
757 	/* clear status bits */
758 	sh_msiof_reset_str(p);
759 
760 	ret = sh_msiof_spi_stop(p, rx);
761 	if (ret) {
762 		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
763 		return ret;
764 	}
765 
766 	if (rx)
767 		dma_sync_single_for_cpu(p->master->dma_rx->device->dev,
768 					p->rx_dma_addr, len,
769 					DMA_FROM_DEVICE);
770 
771 	return 0;
772 
773 stop_reset:
774 	sh_msiof_reset_str(p);
775 	sh_msiof_spi_stop(p, rx);
776 stop_dma:
777 	if (tx)
778 		dmaengine_terminate_all(p->master->dma_tx);
779 no_dma_tx:
780 	if (rx)
781 		dmaengine_terminate_all(p->master->dma_rx);
782 	sh_msiof_write(p, IER, 0);
783 	return ret;
784 }
785 
copy_bswap32(u32 * dst,const u32 * src,unsigned int words)786 static void copy_bswap32(u32 *dst, const u32 *src, unsigned int words)
787 {
788 	/* src or dst can be unaligned, but not both */
789 	if ((unsigned long)src & 3) {
790 		while (words--) {
791 			*dst++ = swab32(get_unaligned(src));
792 			src++;
793 		}
794 	} else if ((unsigned long)dst & 3) {
795 		while (words--) {
796 			put_unaligned(swab32(*src++), dst);
797 			dst++;
798 		}
799 	} else {
800 		while (words--)
801 			*dst++ = swab32(*src++);
802 	}
803 }
804 
copy_wswap32(u32 * dst,const u32 * src,unsigned int words)805 static void copy_wswap32(u32 *dst, const u32 *src, unsigned int words)
806 {
807 	/* src or dst can be unaligned, but not both */
808 	if ((unsigned long)src & 3) {
809 		while (words--) {
810 			*dst++ = swahw32(get_unaligned(src));
811 			src++;
812 		}
813 	} else if ((unsigned long)dst & 3) {
814 		while (words--) {
815 			put_unaligned(swahw32(*src++), dst);
816 			dst++;
817 		}
818 	} else {
819 		while (words--)
820 			*dst++ = swahw32(*src++);
821 	}
822 }
823 
copy_plain32(u32 * dst,const u32 * src,unsigned int words)824 static void copy_plain32(u32 *dst, const u32 *src, unsigned int words)
825 {
826 	memcpy(dst, src, words * 4);
827 }
828 
sh_msiof_transfer_one(struct spi_master * master,struct spi_device * spi,struct spi_transfer * t)829 static int sh_msiof_transfer_one(struct spi_master *master,
830 				 struct spi_device *spi,
831 				 struct spi_transfer *t)
832 {
833 	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
834 	void (*copy32)(u32 *, const u32 *, unsigned int);
835 	void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
836 	void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
837 	const void *tx_buf = t->tx_buf;
838 	void *rx_buf = t->rx_buf;
839 	unsigned int len = t->len;
840 	unsigned int bits = t->bits_per_word;
841 	unsigned int bytes_per_word;
842 	unsigned int words;
843 	int n;
844 	bool swab;
845 	int ret;
846 
847 	/* setup clocks (clock already enabled in chipselect()) */
848 	sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk), t->speed_hz);
849 
850 	while (master->dma_tx && len > 15) {
851 		/*
852 		 *  DMA supports 32-bit words only, hence pack 8-bit and 16-bit
853 		 *  words, with byte resp. word swapping.
854 		 */
855 		unsigned int l = 0;
856 
857 		if (tx_buf)
858 			l = min(len, p->tx_fifo_size * 4);
859 		if (rx_buf)
860 			l = min(len, p->rx_fifo_size * 4);
861 
862 		if (bits <= 8) {
863 			if (l & 3)
864 				break;
865 			copy32 = copy_bswap32;
866 		} else if (bits <= 16) {
867 			if (l & 3)
868 				break;
869 			copy32 = copy_wswap32;
870 		} else {
871 			copy32 = copy_plain32;
872 		}
873 
874 		if (tx_buf)
875 			copy32(p->tx_dma_page, tx_buf, l / 4);
876 
877 		ret = sh_msiof_dma_once(p, tx_buf, rx_buf, l);
878 		if (ret == -EAGAIN) {
879 			pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
880 				     dev_driver_string(&p->pdev->dev),
881 				     dev_name(&p->pdev->dev));
882 			break;
883 		}
884 		if (ret)
885 			return ret;
886 
887 		if (rx_buf) {
888 			copy32(rx_buf, p->rx_dma_page, l / 4);
889 			rx_buf += l;
890 		}
891 		if (tx_buf)
892 			tx_buf += l;
893 
894 		len -= l;
895 		if (!len)
896 			return 0;
897 	}
898 
899 	if (bits <= 8 && len > 15 && !(len & 3)) {
900 		bits = 32;
901 		swab = true;
902 	} else {
903 		swab = false;
904 	}
905 
906 	/* setup bytes per word and fifo read/write functions */
907 	if (bits <= 8) {
908 		bytes_per_word = 1;
909 		tx_fifo = sh_msiof_spi_write_fifo_8;
910 		rx_fifo = sh_msiof_spi_read_fifo_8;
911 	} else if (bits <= 16) {
912 		bytes_per_word = 2;
913 		if ((unsigned long)tx_buf & 0x01)
914 			tx_fifo = sh_msiof_spi_write_fifo_16u;
915 		else
916 			tx_fifo = sh_msiof_spi_write_fifo_16;
917 
918 		if ((unsigned long)rx_buf & 0x01)
919 			rx_fifo = sh_msiof_spi_read_fifo_16u;
920 		else
921 			rx_fifo = sh_msiof_spi_read_fifo_16;
922 	} else if (swab) {
923 		bytes_per_word = 4;
924 		if ((unsigned long)tx_buf & 0x03)
925 			tx_fifo = sh_msiof_spi_write_fifo_s32u;
926 		else
927 			tx_fifo = sh_msiof_spi_write_fifo_s32;
928 
929 		if ((unsigned long)rx_buf & 0x03)
930 			rx_fifo = sh_msiof_spi_read_fifo_s32u;
931 		else
932 			rx_fifo = sh_msiof_spi_read_fifo_s32;
933 	} else {
934 		bytes_per_word = 4;
935 		if ((unsigned long)tx_buf & 0x03)
936 			tx_fifo = sh_msiof_spi_write_fifo_32u;
937 		else
938 			tx_fifo = sh_msiof_spi_write_fifo_32;
939 
940 		if ((unsigned long)rx_buf & 0x03)
941 			rx_fifo = sh_msiof_spi_read_fifo_32u;
942 		else
943 			rx_fifo = sh_msiof_spi_read_fifo_32;
944 	}
945 
946 	/* transfer in fifo sized chunks */
947 	words = len / bytes_per_word;
948 
949 	while (words > 0) {
950 		n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo, tx_buf, rx_buf,
951 					   words, bits);
952 		if (n < 0)
953 			return n;
954 
955 		if (tx_buf)
956 			tx_buf += n * bytes_per_word;
957 		if (rx_buf)
958 			rx_buf += n * bytes_per_word;
959 		words -= n;
960 	}
961 
962 	return 0;
963 }
964 
965 static const struct sh_msiof_chipdata sh_data = {
966 	.tx_fifo_size = 64,
967 	.rx_fifo_size = 64,
968 	.master_flags = 0,
969 };
970 
971 static const struct sh_msiof_chipdata r8a779x_data = {
972 	.tx_fifo_size = 64,
973 	.rx_fifo_size = 64,
974 	.master_flags = SPI_MASTER_MUST_TX,
975 };
976 
977 static const struct of_device_id sh_msiof_match[] = {
978 	{ .compatible = "renesas,sh-msiof",        .data = &sh_data },
979 	{ .compatible = "renesas,sh-mobile-msiof", .data = &sh_data },
980 	{ .compatible = "renesas,msiof-r8a7790",   .data = &r8a779x_data },
981 	{ .compatible = "renesas,msiof-r8a7791",   .data = &r8a779x_data },
982 	{ .compatible = "renesas,msiof-r8a7792",   .data = &r8a779x_data },
983 	{ .compatible = "renesas,msiof-r8a7793",   .data = &r8a779x_data },
984 	{ .compatible = "renesas,msiof-r8a7794",   .data = &r8a779x_data },
985 	{},
986 };
987 MODULE_DEVICE_TABLE(of, sh_msiof_match);
988 
989 #ifdef CONFIG_OF
sh_msiof_spi_parse_dt(struct device * dev)990 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
991 {
992 	struct sh_msiof_spi_info *info;
993 	struct device_node *np = dev->of_node;
994 	u32 num_cs = 1;
995 
996 	info = devm_kzalloc(dev, sizeof(struct sh_msiof_spi_info), GFP_KERNEL);
997 	if (!info)
998 		return NULL;
999 
1000 	/* Parse the MSIOF properties */
1001 	of_property_read_u32(np, "num-cs", &num_cs);
1002 	of_property_read_u32(np, "renesas,tx-fifo-size",
1003 					&info->tx_fifo_override);
1004 	of_property_read_u32(np, "renesas,rx-fifo-size",
1005 					&info->rx_fifo_override);
1006 	of_property_read_u32(np, "renesas,dtdl", &info->dtdl);
1007 	of_property_read_u32(np, "renesas,syncdl", &info->syncdl);
1008 
1009 	info->num_chipselect = num_cs;
1010 
1011 	return info;
1012 }
1013 #else
sh_msiof_spi_parse_dt(struct device * dev)1014 static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
1015 {
1016 	return NULL;
1017 }
1018 #endif
1019 
sh_msiof_request_dma_chan(struct device * dev,enum dma_transfer_direction dir,unsigned int id,dma_addr_t port_addr)1020 static struct dma_chan *sh_msiof_request_dma_chan(struct device *dev,
1021 	enum dma_transfer_direction dir, unsigned int id, dma_addr_t port_addr)
1022 {
1023 	dma_cap_mask_t mask;
1024 	struct dma_chan *chan;
1025 	struct dma_slave_config cfg;
1026 	int ret;
1027 
1028 	dma_cap_zero(mask);
1029 	dma_cap_set(DMA_SLAVE, mask);
1030 
1031 	chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
1032 				(void *)(unsigned long)id, dev,
1033 				dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1034 	if (!chan) {
1035 		dev_warn(dev, "dma_request_slave_channel_compat failed\n");
1036 		return NULL;
1037 	}
1038 
1039 	memset(&cfg, 0, sizeof(cfg));
1040 	cfg.direction = dir;
1041 	if (dir == DMA_MEM_TO_DEV) {
1042 		cfg.dst_addr = port_addr;
1043 		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1044 	} else {
1045 		cfg.src_addr = port_addr;
1046 		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1047 	}
1048 
1049 	ret = dmaengine_slave_config(chan, &cfg);
1050 	if (ret) {
1051 		dev_warn(dev, "dmaengine_slave_config failed %d\n", ret);
1052 		dma_release_channel(chan);
1053 		return NULL;
1054 	}
1055 
1056 	return chan;
1057 }
1058 
sh_msiof_request_dma(struct sh_msiof_spi_priv * p)1059 static int sh_msiof_request_dma(struct sh_msiof_spi_priv *p)
1060 {
1061 	struct platform_device *pdev = p->pdev;
1062 	struct device *dev = &pdev->dev;
1063 	const struct sh_msiof_spi_info *info = dev_get_platdata(dev);
1064 	unsigned int dma_tx_id, dma_rx_id;
1065 	const struct resource *res;
1066 	struct spi_master *master;
1067 	struct device *tx_dev, *rx_dev;
1068 
1069 	if (dev->of_node) {
1070 		/* In the OF case we will get the slave IDs from the DT */
1071 		dma_tx_id = 0;
1072 		dma_rx_id = 0;
1073 	} else if (info && info->dma_tx_id && info->dma_rx_id) {
1074 		dma_tx_id = info->dma_tx_id;
1075 		dma_rx_id = info->dma_rx_id;
1076 	} else {
1077 		/* The driver assumes no error */
1078 		return 0;
1079 	}
1080 
1081 	/* The DMA engine uses the second register set, if present */
1082 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
1083 	if (!res)
1084 		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1085 
1086 	master = p->master;
1087 	master->dma_tx = sh_msiof_request_dma_chan(dev, DMA_MEM_TO_DEV,
1088 						   dma_tx_id,
1089 						   res->start + TFDR);
1090 	if (!master->dma_tx)
1091 		return -ENODEV;
1092 
1093 	master->dma_rx = sh_msiof_request_dma_chan(dev, DMA_DEV_TO_MEM,
1094 						   dma_rx_id,
1095 						   res->start + RFDR);
1096 	if (!master->dma_rx)
1097 		goto free_tx_chan;
1098 
1099 	p->tx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
1100 	if (!p->tx_dma_page)
1101 		goto free_rx_chan;
1102 
1103 	p->rx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
1104 	if (!p->rx_dma_page)
1105 		goto free_tx_page;
1106 
1107 	tx_dev = master->dma_tx->device->dev;
1108 	p->tx_dma_addr = dma_map_single(tx_dev, p->tx_dma_page, PAGE_SIZE,
1109 					DMA_TO_DEVICE);
1110 	if (dma_mapping_error(tx_dev, p->tx_dma_addr))
1111 		goto free_rx_page;
1112 
1113 	rx_dev = master->dma_rx->device->dev;
1114 	p->rx_dma_addr = dma_map_single(rx_dev, p->rx_dma_page, PAGE_SIZE,
1115 					DMA_FROM_DEVICE);
1116 	if (dma_mapping_error(rx_dev, p->rx_dma_addr))
1117 		goto unmap_tx_page;
1118 
1119 	dev_info(dev, "DMA available");
1120 	return 0;
1121 
1122 unmap_tx_page:
1123 	dma_unmap_single(tx_dev, p->tx_dma_addr, PAGE_SIZE, DMA_TO_DEVICE);
1124 free_rx_page:
1125 	free_page((unsigned long)p->rx_dma_page);
1126 free_tx_page:
1127 	free_page((unsigned long)p->tx_dma_page);
1128 free_rx_chan:
1129 	dma_release_channel(master->dma_rx);
1130 free_tx_chan:
1131 	dma_release_channel(master->dma_tx);
1132 	master->dma_tx = NULL;
1133 	return -ENODEV;
1134 }
1135 
sh_msiof_release_dma(struct sh_msiof_spi_priv * p)1136 static void sh_msiof_release_dma(struct sh_msiof_spi_priv *p)
1137 {
1138 	struct spi_master *master = p->master;
1139 	struct device *dev;
1140 
1141 	if (!master->dma_tx)
1142 		return;
1143 
1144 	dev = &p->pdev->dev;
1145 	dma_unmap_single(master->dma_rx->device->dev, p->rx_dma_addr,
1146 			 PAGE_SIZE, DMA_FROM_DEVICE);
1147 	dma_unmap_single(master->dma_tx->device->dev, p->tx_dma_addr,
1148 			 PAGE_SIZE, DMA_TO_DEVICE);
1149 	free_page((unsigned long)p->rx_dma_page);
1150 	free_page((unsigned long)p->tx_dma_page);
1151 	dma_release_channel(master->dma_rx);
1152 	dma_release_channel(master->dma_tx);
1153 }
1154 
sh_msiof_spi_probe(struct platform_device * pdev)1155 static int sh_msiof_spi_probe(struct platform_device *pdev)
1156 {
1157 	struct resource	*r;
1158 	struct spi_master *master;
1159 	const struct of_device_id *of_id;
1160 	struct sh_msiof_spi_priv *p;
1161 	int i;
1162 	int ret;
1163 
1164 	master = spi_alloc_master(&pdev->dev, sizeof(struct sh_msiof_spi_priv));
1165 	if (master == NULL) {
1166 		dev_err(&pdev->dev, "failed to allocate spi master\n");
1167 		return -ENOMEM;
1168 	}
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 		p->chipdata = of_id->data;
1178 		p->info = sh_msiof_spi_parse_dt(&pdev->dev);
1179 	} else {
1180 		p->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 IRQ\n");
1202 		ret = i;
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 = p->chipdata->tx_fifo_size;
1225 	p->rx_fifo_size = p->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 = p->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 
sh_msiof_spi_remove(struct platform_device * pdev)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 #ifdef CONFIG_PM_SLEEP
sh_msiof_spi_suspend(struct device * dev)1280 static int sh_msiof_spi_suspend(struct device *dev)
1281 {
1282 	struct platform_device *pdev = to_platform_device(dev);
1283 	struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
1284 
1285 	return spi_master_suspend(p->master);
1286 }
1287 
sh_msiof_spi_resume(struct device * dev)1288 static int sh_msiof_spi_resume(struct device *dev)
1289 {
1290 	struct platform_device *pdev = to_platform_device(dev);
1291 	struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
1292 
1293 	return spi_master_resume(p->master);
1294 }
1295 
1296 static SIMPLE_DEV_PM_OPS(sh_msiof_spi_pm_ops, sh_msiof_spi_suspend,
1297 			 sh_msiof_spi_resume);
1298 #define DEV_PM_OPS	&sh_msiof_spi_pm_ops
1299 #else
1300 #define DEV_PM_OPS	NULL
1301 #endif /* CONFIG_PM_SLEEP */
1302 
1303 static struct platform_driver sh_msiof_spi_drv = {
1304 	.probe		= sh_msiof_spi_probe,
1305 	.remove		= sh_msiof_spi_remove,
1306 	.id_table	= spi_driver_ids,
1307 	.driver		= {
1308 		.name		= "spi_sh_msiof",
1309 		.pm		= DEV_PM_OPS,
1310 		.of_match_table = of_match_ptr(sh_msiof_match),
1311 	},
1312 };
1313 module_platform_driver(sh_msiof_spi_drv);
1314 
1315 MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
1316 MODULE_AUTHOR("Magnus Damm");
1317 MODULE_LICENSE("GPL v2");
1318 MODULE_ALIAS("platform:spi_sh_msiof");
1319