xref: /openbmc/linux/drivers/spi/spi-rspi.c (revision e65e175b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SH RSPI driver
4  *
5  * Copyright (C) 2012, 2013  Renesas Solutions Corp.
6  * Copyright (C) 2014 Glider bvba
7  *
8  * Based on spi-sh.c:
9  * Copyright (C) 2011 Renesas Solutions Corp.
10  */
11 
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/errno.h>
16 #include <linux/interrupt.h>
17 #include <linux/platform_device.h>
18 #include <linux/io.h>
19 #include <linux/clk.h>
20 #include <linux/dmaengine.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/of_device.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/reset.h>
25 #include <linux/sh_dma.h>
26 #include <linux/spi/spi.h>
27 #include <linux/spi/rspi.h>
28 #include <linux/spinlock.h>
29 
30 #define RSPI_SPCR		0x00	/* Control Register */
31 #define RSPI_SSLP		0x01	/* Slave Select Polarity Register */
32 #define RSPI_SPPCR		0x02	/* Pin Control Register */
33 #define RSPI_SPSR		0x03	/* Status Register */
34 #define RSPI_SPDR		0x04	/* Data Register */
35 #define RSPI_SPSCR		0x08	/* Sequence Control Register */
36 #define RSPI_SPSSR		0x09	/* Sequence Status Register */
37 #define RSPI_SPBR		0x0a	/* Bit Rate Register */
38 #define RSPI_SPDCR		0x0b	/* Data Control Register */
39 #define RSPI_SPCKD		0x0c	/* Clock Delay Register */
40 #define RSPI_SSLND		0x0d	/* Slave Select Negation Delay Register */
41 #define RSPI_SPND		0x0e	/* Next-Access Delay Register */
42 #define RSPI_SPCR2		0x0f	/* Control Register 2 (SH only) */
43 #define RSPI_SPCMD0		0x10	/* Command Register 0 */
44 #define RSPI_SPCMD1		0x12	/* Command Register 1 */
45 #define RSPI_SPCMD2		0x14	/* Command Register 2 */
46 #define RSPI_SPCMD3		0x16	/* Command Register 3 */
47 #define RSPI_SPCMD4		0x18	/* Command Register 4 */
48 #define RSPI_SPCMD5		0x1a	/* Command Register 5 */
49 #define RSPI_SPCMD6		0x1c	/* Command Register 6 */
50 #define RSPI_SPCMD7		0x1e	/* Command Register 7 */
51 #define RSPI_SPCMD(i)		(RSPI_SPCMD0 + (i) * 2)
52 #define RSPI_NUM_SPCMD		8
53 #define RSPI_RZ_NUM_SPCMD	4
54 #define QSPI_NUM_SPCMD		4
55 
56 /* RSPI on RZ only */
57 #define RSPI_SPBFCR		0x20	/* Buffer Control Register */
58 #define RSPI_SPBFDR		0x22	/* Buffer Data Count Setting Register */
59 
60 /* QSPI only */
61 #define QSPI_SPBFCR		0x18	/* Buffer Control Register */
62 #define QSPI_SPBDCR		0x1a	/* Buffer Data Count Register */
63 #define QSPI_SPBMUL0		0x1c	/* Transfer Data Length Multiplier Setting Register 0 */
64 #define QSPI_SPBMUL1		0x20	/* Transfer Data Length Multiplier Setting Register 1 */
65 #define QSPI_SPBMUL2		0x24	/* Transfer Data Length Multiplier Setting Register 2 */
66 #define QSPI_SPBMUL3		0x28	/* Transfer Data Length Multiplier Setting Register 3 */
67 #define QSPI_SPBMUL(i)		(QSPI_SPBMUL0 + (i) * 4)
68 
69 /* SPCR - Control Register */
70 #define SPCR_SPRIE		0x80	/* Receive Interrupt Enable */
71 #define SPCR_SPE		0x40	/* Function Enable */
72 #define SPCR_SPTIE		0x20	/* Transmit Interrupt Enable */
73 #define SPCR_SPEIE		0x10	/* Error Interrupt Enable */
74 #define SPCR_MSTR		0x08	/* Master/Slave Mode Select */
75 #define SPCR_MODFEN		0x04	/* Mode Fault Error Detection Enable */
76 /* RSPI on SH only */
77 #define SPCR_TXMD		0x02	/* TX Only Mode (vs. Full Duplex) */
78 #define SPCR_SPMS		0x01	/* 3-wire Mode (vs. 4-wire) */
79 /* QSPI on R-Car Gen2 only */
80 #define SPCR_WSWAP		0x02	/* Word Swap of read-data for DMAC */
81 #define SPCR_BSWAP		0x01	/* Byte Swap of read-data for DMAC */
82 
83 /* SSLP - Slave Select Polarity Register */
84 #define SSLP_SSLP(i)		BIT(i)	/* SSLi Signal Polarity Setting */
85 
86 /* SPPCR - Pin Control Register */
87 #define SPPCR_MOIFE		0x20	/* MOSI Idle Value Fixing Enable */
88 #define SPPCR_MOIFV		0x10	/* MOSI Idle Fixed Value */
89 #define SPPCR_SPOM		0x04
90 #define SPPCR_SPLP2		0x02	/* Loopback Mode 2 (non-inverting) */
91 #define SPPCR_SPLP		0x01	/* Loopback Mode (inverting) */
92 
93 #define SPPCR_IO3FV		0x04	/* Single-/Dual-SPI Mode IO3 Output Fixed Value */
94 #define SPPCR_IO2FV		0x04	/* Single-/Dual-SPI Mode IO2 Output Fixed Value */
95 
96 /* SPSR - Status Register */
97 #define SPSR_SPRF		0x80	/* Receive Buffer Full Flag */
98 #define SPSR_TEND		0x40	/* Transmit End */
99 #define SPSR_SPTEF		0x20	/* Transmit Buffer Empty Flag */
100 #define SPSR_PERF		0x08	/* Parity Error Flag */
101 #define SPSR_MODF		0x04	/* Mode Fault Error Flag */
102 #define SPSR_IDLNF		0x02	/* RSPI Idle Flag */
103 #define SPSR_OVRF		0x01	/* Overrun Error Flag (RSPI only) */
104 
105 /* SPSCR - Sequence Control Register */
106 #define SPSCR_SPSLN_MASK	0x07	/* Sequence Length Specification */
107 
108 /* SPSSR - Sequence Status Register */
109 #define SPSSR_SPECM_MASK	0x70	/* Command Error Mask */
110 #define SPSSR_SPCP_MASK		0x07	/* Command Pointer Mask */
111 
112 /* SPDCR - Data Control Register */
113 #define SPDCR_TXDMY		0x80	/* Dummy Data Transmission Enable */
114 #define SPDCR_SPLW1		0x40	/* Access Width Specification (RZ) */
115 #define SPDCR_SPLW0		0x20	/* Access Width Specification (RZ) */
116 #define SPDCR_SPLLWORD		(SPDCR_SPLW1 | SPDCR_SPLW0)
117 #define SPDCR_SPLWORD		SPDCR_SPLW1
118 #define SPDCR_SPLBYTE		SPDCR_SPLW0
119 #define SPDCR_SPLW		0x20	/* Access Width Specification (SH) */
120 #define SPDCR_SPRDTD		0x10	/* Receive Transmit Data Select (SH) */
121 #define SPDCR_SLSEL1		0x08
122 #define SPDCR_SLSEL0		0x04
123 #define SPDCR_SLSEL_MASK	0x0c	/* SSL1 Output Select (SH) */
124 #define SPDCR_SPFC1		0x02
125 #define SPDCR_SPFC0		0x01
126 #define SPDCR_SPFC_MASK		0x03	/* Frame Count Setting (1-4) (SH) */
127 
128 /* SPCKD - Clock Delay Register */
129 #define SPCKD_SCKDL_MASK	0x07	/* Clock Delay Setting (1-8) */
130 
131 /* SSLND - Slave Select Negation Delay Register */
132 #define SSLND_SLNDL_MASK	0x07	/* SSL Negation Delay Setting (1-8) */
133 
134 /* SPND - Next-Access Delay Register */
135 #define SPND_SPNDL_MASK		0x07	/* Next-Access Delay Setting (1-8) */
136 
137 /* SPCR2 - Control Register 2 */
138 #define SPCR2_PTE		0x08	/* Parity Self-Test Enable */
139 #define SPCR2_SPIE		0x04	/* Idle Interrupt Enable */
140 #define SPCR2_SPOE		0x02	/* Odd Parity Enable (vs. Even) */
141 #define SPCR2_SPPE		0x01	/* Parity Enable */
142 
143 /* SPCMDn - Command Registers */
144 #define SPCMD_SCKDEN		0x8000	/* Clock Delay Setting Enable */
145 #define SPCMD_SLNDEN		0x4000	/* SSL Negation Delay Setting Enable */
146 #define SPCMD_SPNDEN		0x2000	/* Next-Access Delay Enable */
147 #define SPCMD_LSBF		0x1000	/* LSB First */
148 #define SPCMD_SPB_MASK		0x0f00	/* Data Length Setting */
149 #define SPCMD_SPB_8_TO_16(bit)	(((bit - 1) << 8) & SPCMD_SPB_MASK)
150 #define SPCMD_SPB_8BIT		0x0000	/* QSPI only */
151 #define SPCMD_SPB_16BIT		0x0100
152 #define SPCMD_SPB_20BIT		0x0000
153 #define SPCMD_SPB_24BIT		0x0100
154 #define SPCMD_SPB_32BIT		0x0200
155 #define SPCMD_SSLKP		0x0080	/* SSL Signal Level Keeping */
156 #define SPCMD_SPIMOD_MASK	0x0060	/* SPI Operating Mode (QSPI only) */
157 #define SPCMD_SPIMOD1		0x0040
158 #define SPCMD_SPIMOD0		0x0020
159 #define SPCMD_SPIMOD_SINGLE	0
160 #define SPCMD_SPIMOD_DUAL	SPCMD_SPIMOD0
161 #define SPCMD_SPIMOD_QUAD	SPCMD_SPIMOD1
162 #define SPCMD_SPRW		0x0010	/* SPI Read/Write Access (Dual/Quad) */
163 #define SPCMD_SSLA(i)		((i) << 4)	/* SSL Assert Signal Setting */
164 #define SPCMD_BRDV_MASK		0x000c	/* Bit Rate Division Setting */
165 #define SPCMD_BRDV(brdv)	((brdv) << 2)
166 #define SPCMD_CPOL		0x0002	/* Clock Polarity Setting */
167 #define SPCMD_CPHA		0x0001	/* Clock Phase Setting */
168 
169 /* SPBFCR - Buffer Control Register */
170 #define SPBFCR_TXRST		0x80	/* Transmit Buffer Data Reset */
171 #define SPBFCR_RXRST		0x40	/* Receive Buffer Data Reset */
172 #define SPBFCR_TXTRG_MASK	0x30	/* Transmit Buffer Data Triggering Number */
173 #define SPBFCR_RXTRG_MASK	0x07	/* Receive Buffer Data Triggering Number */
174 /* QSPI on R-Car Gen2 */
175 #define SPBFCR_TXTRG_1B		0x00	/* 31 bytes (1 byte available) */
176 #define SPBFCR_TXTRG_32B	0x30	/* 0 byte (32 bytes available) */
177 #define SPBFCR_RXTRG_1B		0x00	/* 1 byte (31 bytes available) */
178 #define SPBFCR_RXTRG_32B	0x07	/* 32 bytes (0 byte available) */
179 
180 #define QSPI_BUFFER_SIZE        32u
181 
182 struct rspi_data {
183 	void __iomem *addr;
184 	u32 speed_hz;
185 	struct spi_controller *ctlr;
186 	struct platform_device *pdev;
187 	wait_queue_head_t wait;
188 	spinlock_t lock;		/* Protects RMW-access to RSPI_SSLP */
189 	struct clk *clk;
190 	u16 spcmd;
191 	u8 spsr;
192 	u8 sppcr;
193 	int rx_irq, tx_irq;
194 	const struct spi_ops *ops;
195 
196 	unsigned dma_callbacked:1;
197 	unsigned byte_access:1;
198 };
199 
200 static void rspi_write8(const struct rspi_data *rspi, u8 data, u16 offset)
201 {
202 	iowrite8(data, rspi->addr + offset);
203 }
204 
205 static void rspi_write16(const struct rspi_data *rspi, u16 data, u16 offset)
206 {
207 	iowrite16(data, rspi->addr + offset);
208 }
209 
210 static void rspi_write32(const struct rspi_data *rspi, u32 data, u16 offset)
211 {
212 	iowrite32(data, rspi->addr + offset);
213 }
214 
215 static u8 rspi_read8(const struct rspi_data *rspi, u16 offset)
216 {
217 	return ioread8(rspi->addr + offset);
218 }
219 
220 static u16 rspi_read16(const struct rspi_data *rspi, u16 offset)
221 {
222 	return ioread16(rspi->addr + offset);
223 }
224 
225 static void rspi_write_data(const struct rspi_data *rspi, u16 data)
226 {
227 	if (rspi->byte_access)
228 		rspi_write8(rspi, data, RSPI_SPDR);
229 	else /* 16 bit */
230 		rspi_write16(rspi, data, RSPI_SPDR);
231 }
232 
233 static u16 rspi_read_data(const struct rspi_data *rspi)
234 {
235 	if (rspi->byte_access)
236 		return rspi_read8(rspi, RSPI_SPDR);
237 	else /* 16 bit */
238 		return rspi_read16(rspi, RSPI_SPDR);
239 }
240 
241 /* optional functions */
242 struct spi_ops {
243 	int (*set_config_register)(struct rspi_data *rspi, int access_size);
244 	int (*transfer_one)(struct spi_controller *ctlr,
245 			    struct spi_device *spi, struct spi_transfer *xfer);
246 	u16 extra_mode_bits;
247 	u16 min_div;
248 	u16 max_div;
249 	u16 flags;
250 	u16 fifo_size;
251 	u8 num_hw_ss;
252 };
253 
254 static void rspi_set_rate(struct rspi_data *rspi)
255 {
256 	unsigned long clksrc;
257 	int brdv = 0, spbr;
258 
259 	clksrc = clk_get_rate(rspi->clk);
260 	spbr = DIV_ROUND_UP(clksrc, 2 * rspi->speed_hz) - 1;
261 	while (spbr > 255 && brdv < 3) {
262 		brdv++;
263 		spbr = DIV_ROUND_UP(spbr + 1, 2) - 1;
264 	}
265 
266 	rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
267 	rspi->spcmd |= SPCMD_BRDV(brdv);
268 	rspi->speed_hz = DIV_ROUND_UP(clksrc, (2U << brdv) * (spbr + 1));
269 }
270 
271 /*
272  * functions for RSPI on legacy SH
273  */
274 static int rspi_set_config_register(struct rspi_data *rspi, int access_size)
275 {
276 	/* Sets output mode, MOSI signal, and (optionally) loopback */
277 	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
278 
279 	/* Sets transfer bit rate */
280 	rspi_set_rate(rspi);
281 
282 	/* Disable dummy transmission, set 16-bit word access, 1 frame */
283 	rspi_write8(rspi, 0, RSPI_SPDCR);
284 	rspi->byte_access = 0;
285 
286 	/* Sets RSPCK, SSL, next-access delay value */
287 	rspi_write8(rspi, 0x00, RSPI_SPCKD);
288 	rspi_write8(rspi, 0x00, RSPI_SSLND);
289 	rspi_write8(rspi, 0x00, RSPI_SPND);
290 
291 	/* Sets parity, interrupt mask */
292 	rspi_write8(rspi, 0x00, RSPI_SPCR2);
293 
294 	/* Resets sequencer */
295 	rspi_write8(rspi, 0, RSPI_SPSCR);
296 	rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
297 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
298 
299 	/* Sets RSPI mode */
300 	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
301 
302 	return 0;
303 }
304 
305 /*
306  * functions for RSPI on RZ
307  */
308 static int rspi_rz_set_config_register(struct rspi_data *rspi, int access_size)
309 {
310 	/* Sets output mode, MOSI signal, and (optionally) loopback */
311 	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
312 
313 	/* Sets transfer bit rate */
314 	rspi_set_rate(rspi);
315 
316 	/* Disable dummy transmission, set byte access */
317 	rspi_write8(rspi, SPDCR_SPLBYTE, RSPI_SPDCR);
318 	rspi->byte_access = 1;
319 
320 	/* Sets RSPCK, SSL, next-access delay value */
321 	rspi_write8(rspi, 0x00, RSPI_SPCKD);
322 	rspi_write8(rspi, 0x00, RSPI_SSLND);
323 	rspi_write8(rspi, 0x00, RSPI_SPND);
324 
325 	/* Resets sequencer */
326 	rspi_write8(rspi, 0, RSPI_SPSCR);
327 	rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
328 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
329 
330 	/* Sets RSPI mode */
331 	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
332 
333 	return 0;
334 }
335 
336 /*
337  * functions for QSPI
338  */
339 static int qspi_set_config_register(struct rspi_data *rspi, int access_size)
340 {
341 	unsigned long clksrc;
342 	int brdv = 0, spbr;
343 
344 	/* Sets output mode, MOSI signal, and (optionally) loopback */
345 	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
346 
347 	/* Sets transfer bit rate */
348 	clksrc = clk_get_rate(rspi->clk);
349 	if (rspi->speed_hz >= clksrc) {
350 		spbr = 0;
351 		rspi->speed_hz = clksrc;
352 	} else {
353 		spbr = DIV_ROUND_UP(clksrc, 2 * rspi->speed_hz);
354 		while (spbr > 255 && brdv < 3) {
355 			brdv++;
356 			spbr = DIV_ROUND_UP(spbr, 2);
357 		}
358 		spbr = clamp(spbr, 0, 255);
359 		rspi->speed_hz = DIV_ROUND_UP(clksrc, (2U << brdv) * spbr);
360 	}
361 	rspi_write8(rspi, spbr, RSPI_SPBR);
362 	rspi->spcmd |= SPCMD_BRDV(brdv);
363 
364 	/* Disable dummy transmission, set byte access */
365 	rspi_write8(rspi, 0, RSPI_SPDCR);
366 	rspi->byte_access = 1;
367 
368 	/* Sets RSPCK, SSL, next-access delay value */
369 	rspi_write8(rspi, 0x00, RSPI_SPCKD);
370 	rspi_write8(rspi, 0x00, RSPI_SSLND);
371 	rspi_write8(rspi, 0x00, RSPI_SPND);
372 
373 	/* Data Length Setting */
374 	if (access_size == 8)
375 		rspi->spcmd |= SPCMD_SPB_8BIT;
376 	else if (access_size == 16)
377 		rspi->spcmd |= SPCMD_SPB_16BIT;
378 	else
379 		rspi->spcmd |= SPCMD_SPB_32BIT;
380 
381 	rspi->spcmd |= SPCMD_SCKDEN | SPCMD_SLNDEN | SPCMD_SPNDEN;
382 
383 	/* Resets transfer data length */
384 	rspi_write32(rspi, 0, QSPI_SPBMUL0);
385 
386 	/* Resets transmit and receive buffer */
387 	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
388 	/* Sets buffer to allow normal operation */
389 	rspi_write8(rspi, 0x00, QSPI_SPBFCR);
390 
391 	/* Resets sequencer */
392 	rspi_write8(rspi, 0, RSPI_SPSCR);
393 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
394 
395 	/* Sets RSPI mode */
396 	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
397 
398 	return 0;
399 }
400 
401 static void qspi_update(const struct rspi_data *rspi, u8 mask, u8 val, u8 reg)
402 {
403 	u8 data;
404 
405 	data = rspi_read8(rspi, reg);
406 	data &= ~mask;
407 	data |= (val & mask);
408 	rspi_write8(rspi, data, reg);
409 }
410 
411 static unsigned int qspi_set_send_trigger(struct rspi_data *rspi,
412 					  unsigned int len)
413 {
414 	unsigned int n;
415 
416 	n = min(len, QSPI_BUFFER_SIZE);
417 
418 	if (len >= QSPI_BUFFER_SIZE) {
419 		/* sets triggering number to 32 bytes */
420 		qspi_update(rspi, SPBFCR_TXTRG_MASK,
421 			     SPBFCR_TXTRG_32B, QSPI_SPBFCR);
422 	} else {
423 		/* sets triggering number to 1 byte */
424 		qspi_update(rspi, SPBFCR_TXTRG_MASK,
425 			     SPBFCR_TXTRG_1B, QSPI_SPBFCR);
426 	}
427 
428 	return n;
429 }
430 
431 static int qspi_set_receive_trigger(struct rspi_data *rspi, unsigned int len)
432 {
433 	unsigned int n;
434 
435 	n = min(len, QSPI_BUFFER_SIZE);
436 
437 	if (len >= QSPI_BUFFER_SIZE) {
438 		/* sets triggering number to 32 bytes */
439 		qspi_update(rspi, SPBFCR_RXTRG_MASK,
440 			     SPBFCR_RXTRG_32B, QSPI_SPBFCR);
441 	} else {
442 		/* sets triggering number to 1 byte */
443 		qspi_update(rspi, SPBFCR_RXTRG_MASK,
444 			     SPBFCR_RXTRG_1B, QSPI_SPBFCR);
445 	}
446 	return n;
447 }
448 
449 static void rspi_enable_irq(const struct rspi_data *rspi, u8 enable)
450 {
451 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | enable, RSPI_SPCR);
452 }
453 
454 static void rspi_disable_irq(const struct rspi_data *rspi, u8 disable)
455 {
456 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~disable, RSPI_SPCR);
457 }
458 
459 static int rspi_wait_for_interrupt(struct rspi_data *rspi, u8 wait_mask,
460 				   u8 enable_bit)
461 {
462 	int ret;
463 
464 	rspi->spsr = rspi_read8(rspi, RSPI_SPSR);
465 	if (rspi->spsr & wait_mask)
466 		return 0;
467 
468 	rspi_enable_irq(rspi, enable_bit);
469 	ret = wait_event_timeout(rspi->wait, rspi->spsr & wait_mask, HZ);
470 	if (ret == 0 && !(rspi->spsr & wait_mask))
471 		return -ETIMEDOUT;
472 
473 	return 0;
474 }
475 
476 static inline int rspi_wait_for_tx_empty(struct rspi_data *rspi)
477 {
478 	return rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
479 }
480 
481 static inline int rspi_wait_for_rx_full(struct rspi_data *rspi)
482 {
483 	return rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE);
484 }
485 
486 static int rspi_data_out(struct rspi_data *rspi, u8 data)
487 {
488 	int error = rspi_wait_for_tx_empty(rspi);
489 	if (error < 0) {
490 		dev_err(&rspi->ctlr->dev, "transmit timeout\n");
491 		return error;
492 	}
493 	rspi_write_data(rspi, data);
494 	return 0;
495 }
496 
497 static int rspi_data_in(struct rspi_data *rspi)
498 {
499 	int error;
500 	u8 data;
501 
502 	error = rspi_wait_for_rx_full(rspi);
503 	if (error < 0) {
504 		dev_err(&rspi->ctlr->dev, "receive timeout\n");
505 		return error;
506 	}
507 	data = rspi_read_data(rspi);
508 	return data;
509 }
510 
511 static int rspi_pio_transfer(struct rspi_data *rspi, const u8 *tx, u8 *rx,
512 			     unsigned int n)
513 {
514 	while (n-- > 0) {
515 		if (tx) {
516 			int ret = rspi_data_out(rspi, *tx++);
517 			if (ret < 0)
518 				return ret;
519 		}
520 		if (rx) {
521 			int ret = rspi_data_in(rspi);
522 			if (ret < 0)
523 				return ret;
524 			*rx++ = ret;
525 		}
526 	}
527 
528 	return 0;
529 }
530 
531 static void rspi_dma_complete(void *arg)
532 {
533 	struct rspi_data *rspi = arg;
534 
535 	rspi->dma_callbacked = 1;
536 	wake_up_interruptible(&rspi->wait);
537 }
538 
539 static int rspi_dma_transfer(struct rspi_data *rspi, struct sg_table *tx,
540 			     struct sg_table *rx)
541 {
542 	struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
543 	u8 irq_mask = 0;
544 	unsigned int other_irq = 0;
545 	dma_cookie_t cookie;
546 	int ret;
547 
548 	/* First prepare and submit the DMA request(s), as this may fail */
549 	if (rx) {
550 		desc_rx = dmaengine_prep_slave_sg(rspi->ctlr->dma_rx, rx->sgl,
551 					rx->nents, DMA_DEV_TO_MEM,
552 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
553 		if (!desc_rx) {
554 			ret = -EAGAIN;
555 			goto no_dma_rx;
556 		}
557 
558 		desc_rx->callback = rspi_dma_complete;
559 		desc_rx->callback_param = rspi;
560 		cookie = dmaengine_submit(desc_rx);
561 		if (dma_submit_error(cookie)) {
562 			ret = cookie;
563 			goto no_dma_rx;
564 		}
565 
566 		irq_mask |= SPCR_SPRIE;
567 	}
568 
569 	if (tx) {
570 		desc_tx = dmaengine_prep_slave_sg(rspi->ctlr->dma_tx, tx->sgl,
571 					tx->nents, DMA_MEM_TO_DEV,
572 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
573 		if (!desc_tx) {
574 			ret = -EAGAIN;
575 			goto no_dma_tx;
576 		}
577 
578 		if (rx) {
579 			/* No callback */
580 			desc_tx->callback = NULL;
581 		} else {
582 			desc_tx->callback = rspi_dma_complete;
583 			desc_tx->callback_param = rspi;
584 		}
585 		cookie = dmaengine_submit(desc_tx);
586 		if (dma_submit_error(cookie)) {
587 			ret = cookie;
588 			goto no_dma_tx;
589 		}
590 
591 		irq_mask |= SPCR_SPTIE;
592 	}
593 
594 	/*
595 	 * DMAC needs SPxIE, but if SPxIE is set, the IRQ routine will be
596 	 * called. So, this driver disables the IRQ while DMA transfer.
597 	 */
598 	if (tx)
599 		disable_irq(other_irq = rspi->tx_irq);
600 	if (rx && rspi->rx_irq != other_irq)
601 		disable_irq(rspi->rx_irq);
602 
603 	rspi_enable_irq(rspi, irq_mask);
604 	rspi->dma_callbacked = 0;
605 
606 	/* Now start DMA */
607 	if (rx)
608 		dma_async_issue_pending(rspi->ctlr->dma_rx);
609 	if (tx)
610 		dma_async_issue_pending(rspi->ctlr->dma_tx);
611 
612 	ret = wait_event_interruptible_timeout(rspi->wait,
613 					       rspi->dma_callbacked, HZ);
614 	if (ret > 0 && rspi->dma_callbacked) {
615 		ret = 0;
616 		if (tx)
617 			dmaengine_synchronize(rspi->ctlr->dma_tx);
618 		if (rx)
619 			dmaengine_synchronize(rspi->ctlr->dma_rx);
620 	} else {
621 		if (!ret) {
622 			dev_err(&rspi->ctlr->dev, "DMA timeout\n");
623 			ret = -ETIMEDOUT;
624 		}
625 		if (tx)
626 			dmaengine_terminate_sync(rspi->ctlr->dma_tx);
627 		if (rx)
628 			dmaengine_terminate_sync(rspi->ctlr->dma_rx);
629 	}
630 
631 	rspi_disable_irq(rspi, irq_mask);
632 
633 	if (tx)
634 		enable_irq(rspi->tx_irq);
635 	if (rx && rspi->rx_irq != other_irq)
636 		enable_irq(rspi->rx_irq);
637 
638 	return ret;
639 
640 no_dma_tx:
641 	if (rx)
642 		dmaengine_terminate_sync(rspi->ctlr->dma_rx);
643 no_dma_rx:
644 	if (ret == -EAGAIN) {
645 		dev_warn_once(&rspi->ctlr->dev,
646 			      "DMA not available, falling back to PIO\n");
647 	}
648 	return ret;
649 }
650 
651 static void rspi_receive_init(const struct rspi_data *rspi)
652 {
653 	u8 spsr;
654 
655 	spsr = rspi_read8(rspi, RSPI_SPSR);
656 	if (spsr & SPSR_SPRF)
657 		rspi_read_data(rspi);	/* dummy read */
658 	if (spsr & SPSR_OVRF)
659 		rspi_write8(rspi, rspi_read8(rspi, RSPI_SPSR) & ~SPSR_OVRF,
660 			    RSPI_SPSR);
661 }
662 
663 static void rspi_rz_receive_init(const struct rspi_data *rspi)
664 {
665 	rspi_receive_init(rspi);
666 	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, RSPI_SPBFCR);
667 	rspi_write8(rspi, 0, RSPI_SPBFCR);
668 }
669 
670 static void qspi_receive_init(const struct rspi_data *rspi)
671 {
672 	u8 spsr;
673 
674 	spsr = rspi_read8(rspi, RSPI_SPSR);
675 	if (spsr & SPSR_SPRF)
676 		rspi_read_data(rspi);   /* dummy read */
677 	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
678 	rspi_write8(rspi, 0, QSPI_SPBFCR);
679 }
680 
681 static bool __rspi_can_dma(const struct rspi_data *rspi,
682 			   const struct spi_transfer *xfer)
683 {
684 	return xfer->len > rspi->ops->fifo_size;
685 }
686 
687 static bool rspi_can_dma(struct spi_controller *ctlr, struct spi_device *spi,
688 			 struct spi_transfer *xfer)
689 {
690 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
691 
692 	return __rspi_can_dma(rspi, xfer);
693 }
694 
695 static int rspi_dma_check_then_transfer(struct rspi_data *rspi,
696 					 struct spi_transfer *xfer)
697 {
698 	if (!rspi->ctlr->can_dma || !__rspi_can_dma(rspi, xfer))
699 		return -EAGAIN;
700 
701 	/* rx_buf can be NULL on RSPI on SH in TX-only Mode */
702 	return rspi_dma_transfer(rspi, &xfer->tx_sg,
703 				xfer->rx_buf ? &xfer->rx_sg : NULL);
704 }
705 
706 static int rspi_common_transfer(struct rspi_data *rspi,
707 				struct spi_transfer *xfer)
708 {
709 	int ret;
710 
711 	xfer->effective_speed_hz = rspi->speed_hz;
712 
713 	ret = rspi_dma_check_then_transfer(rspi, xfer);
714 	if (ret != -EAGAIN)
715 		return ret;
716 
717 	ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len);
718 	if (ret < 0)
719 		return ret;
720 
721 	/* Wait for the last transmission */
722 	rspi_wait_for_tx_empty(rspi);
723 
724 	return 0;
725 }
726 
727 static int rspi_transfer_one(struct spi_controller *ctlr,
728 			     struct spi_device *spi, struct spi_transfer *xfer)
729 {
730 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
731 	u8 spcr;
732 
733 	spcr = rspi_read8(rspi, RSPI_SPCR);
734 	if (xfer->rx_buf) {
735 		rspi_receive_init(rspi);
736 		spcr &= ~SPCR_TXMD;
737 	} else {
738 		spcr |= SPCR_TXMD;
739 	}
740 	rspi_write8(rspi, spcr, RSPI_SPCR);
741 
742 	return rspi_common_transfer(rspi, xfer);
743 }
744 
745 static int rspi_rz_transfer_one(struct spi_controller *ctlr,
746 				struct spi_device *spi,
747 				struct spi_transfer *xfer)
748 {
749 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
750 
751 	rspi_rz_receive_init(rspi);
752 
753 	return rspi_common_transfer(rspi, xfer);
754 }
755 
756 static int qspi_trigger_transfer_out_in(struct rspi_data *rspi, const u8 *tx,
757 					u8 *rx, unsigned int len)
758 {
759 	unsigned int i, n;
760 	int ret;
761 
762 	while (len > 0) {
763 		n = qspi_set_send_trigger(rspi, len);
764 		qspi_set_receive_trigger(rspi, len);
765 		ret = rspi_wait_for_tx_empty(rspi);
766 		if (ret < 0) {
767 			dev_err(&rspi->ctlr->dev, "transmit timeout\n");
768 			return ret;
769 		}
770 		for (i = 0; i < n; i++)
771 			rspi_write_data(rspi, *tx++);
772 
773 		ret = rspi_wait_for_rx_full(rspi);
774 		if (ret < 0) {
775 			dev_err(&rspi->ctlr->dev, "receive timeout\n");
776 			return ret;
777 		}
778 		for (i = 0; i < n; i++)
779 			*rx++ = rspi_read_data(rspi);
780 
781 		len -= n;
782 	}
783 
784 	return 0;
785 }
786 
787 static int qspi_transfer_out_in(struct rspi_data *rspi,
788 				struct spi_transfer *xfer)
789 {
790 	int ret;
791 
792 	qspi_receive_init(rspi);
793 
794 	ret = rspi_dma_check_then_transfer(rspi, xfer);
795 	if (ret != -EAGAIN)
796 		return ret;
797 
798 	return qspi_trigger_transfer_out_in(rspi, xfer->tx_buf,
799 					    xfer->rx_buf, xfer->len);
800 }
801 
802 static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer)
803 {
804 	const u8 *tx = xfer->tx_buf;
805 	unsigned int n = xfer->len;
806 	unsigned int i, len;
807 	int ret;
808 
809 	if (rspi->ctlr->can_dma && __rspi_can_dma(rspi, xfer)) {
810 		ret = rspi_dma_transfer(rspi, &xfer->tx_sg, NULL);
811 		if (ret != -EAGAIN)
812 			return ret;
813 	}
814 
815 	while (n > 0) {
816 		len = qspi_set_send_trigger(rspi, n);
817 		ret = rspi_wait_for_tx_empty(rspi);
818 		if (ret < 0) {
819 			dev_err(&rspi->ctlr->dev, "transmit timeout\n");
820 			return ret;
821 		}
822 		for (i = 0; i < len; i++)
823 			rspi_write_data(rspi, *tx++);
824 
825 		n -= len;
826 	}
827 
828 	/* Wait for the last transmission */
829 	rspi_wait_for_tx_empty(rspi);
830 
831 	return 0;
832 }
833 
834 static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer)
835 {
836 	u8 *rx = xfer->rx_buf;
837 	unsigned int n = xfer->len;
838 	unsigned int i, len;
839 	int ret;
840 
841 	if (rspi->ctlr->can_dma && __rspi_can_dma(rspi, xfer)) {
842 		ret = rspi_dma_transfer(rspi, NULL, &xfer->rx_sg);
843 		if (ret != -EAGAIN)
844 			return ret;
845 	}
846 
847 	while (n > 0) {
848 		len = qspi_set_receive_trigger(rspi, n);
849 		ret = rspi_wait_for_rx_full(rspi);
850 		if (ret < 0) {
851 			dev_err(&rspi->ctlr->dev, "receive timeout\n");
852 			return ret;
853 		}
854 		for (i = 0; i < len; i++)
855 			*rx++ = rspi_read_data(rspi);
856 
857 		n -= len;
858 	}
859 
860 	return 0;
861 }
862 
863 static int qspi_transfer_one(struct spi_controller *ctlr,
864 			     struct spi_device *spi, struct spi_transfer *xfer)
865 {
866 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
867 
868 	xfer->effective_speed_hz = rspi->speed_hz;
869 	if (spi->mode & SPI_LOOP) {
870 		return qspi_transfer_out_in(rspi, xfer);
871 	} else if (xfer->tx_nbits > SPI_NBITS_SINGLE) {
872 		/* Quad or Dual SPI Write */
873 		return qspi_transfer_out(rspi, xfer);
874 	} else if (xfer->rx_nbits > SPI_NBITS_SINGLE) {
875 		/* Quad or Dual SPI Read */
876 		return qspi_transfer_in(rspi, xfer);
877 	} else {
878 		/* Single SPI Transfer */
879 		return qspi_transfer_out_in(rspi, xfer);
880 	}
881 }
882 
883 static u16 qspi_transfer_mode(const struct spi_transfer *xfer)
884 {
885 	if (xfer->tx_buf)
886 		switch (xfer->tx_nbits) {
887 		case SPI_NBITS_QUAD:
888 			return SPCMD_SPIMOD_QUAD;
889 		case SPI_NBITS_DUAL:
890 			return SPCMD_SPIMOD_DUAL;
891 		default:
892 			return 0;
893 		}
894 	if (xfer->rx_buf)
895 		switch (xfer->rx_nbits) {
896 		case SPI_NBITS_QUAD:
897 			return SPCMD_SPIMOD_QUAD | SPCMD_SPRW;
898 		case SPI_NBITS_DUAL:
899 			return SPCMD_SPIMOD_DUAL | SPCMD_SPRW;
900 		default:
901 			return 0;
902 		}
903 
904 	return 0;
905 }
906 
907 static int qspi_setup_sequencer(struct rspi_data *rspi,
908 				const struct spi_message *msg)
909 {
910 	const struct spi_transfer *xfer;
911 	unsigned int i = 0, len = 0;
912 	u16 current_mode = 0xffff, mode;
913 
914 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
915 		mode = qspi_transfer_mode(xfer);
916 		if (mode == current_mode) {
917 			len += xfer->len;
918 			continue;
919 		}
920 
921 		/* Transfer mode change */
922 		if (i) {
923 			/* Set transfer data length of previous transfer */
924 			rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
925 		}
926 
927 		if (i >= QSPI_NUM_SPCMD) {
928 			dev_err(&msg->spi->dev,
929 				"Too many different transfer modes");
930 			return -EINVAL;
931 		}
932 
933 		/* Program transfer mode for this transfer */
934 		rspi_write16(rspi, rspi->spcmd | mode, RSPI_SPCMD(i));
935 		current_mode = mode;
936 		len = xfer->len;
937 		i++;
938 	}
939 	if (i) {
940 		/* Set final transfer data length and sequence length */
941 		rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
942 		rspi_write8(rspi, i - 1, RSPI_SPSCR);
943 	}
944 
945 	return 0;
946 }
947 
948 static int rspi_setup(struct spi_device *spi)
949 {
950 	struct rspi_data *rspi = spi_controller_get_devdata(spi->controller);
951 	u8 sslp;
952 
953 	if (spi->cs_gpiod)
954 		return 0;
955 
956 	pm_runtime_get_sync(&rspi->pdev->dev);
957 	spin_lock_irq(&rspi->lock);
958 
959 	sslp = rspi_read8(rspi, RSPI_SSLP);
960 	if (spi->mode & SPI_CS_HIGH)
961 		sslp |= SSLP_SSLP(spi->chip_select);
962 	else
963 		sslp &= ~SSLP_SSLP(spi->chip_select);
964 	rspi_write8(rspi, sslp, RSPI_SSLP);
965 
966 	spin_unlock_irq(&rspi->lock);
967 	pm_runtime_put(&rspi->pdev->dev);
968 	return 0;
969 }
970 
971 static int rspi_prepare_message(struct spi_controller *ctlr,
972 				struct spi_message *msg)
973 {
974 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
975 	struct spi_device *spi = msg->spi;
976 	const struct spi_transfer *xfer;
977 	int ret;
978 
979 	/*
980 	 * As the Bit Rate Register must not be changed while the device is
981 	 * active, all transfers in a message must use the same bit rate.
982 	 * In theory, the sequencer could be enabled, and each Command Register
983 	 * could divide the base bit rate by a different value.
984 	 * However, most RSPI variants do not have Transfer Data Length
985 	 * Multiplier Setting Registers, so each sequence step would be limited
986 	 * to a single word, making this feature unsuitable for large
987 	 * transfers, which would gain most from it.
988 	 */
989 	rspi->speed_hz = spi->max_speed_hz;
990 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
991 		if (xfer->speed_hz < rspi->speed_hz)
992 			rspi->speed_hz = xfer->speed_hz;
993 	}
994 
995 	rspi->spcmd = SPCMD_SSLKP;
996 	if (spi->mode & SPI_CPOL)
997 		rspi->spcmd |= SPCMD_CPOL;
998 	if (spi->mode & SPI_CPHA)
999 		rspi->spcmd |= SPCMD_CPHA;
1000 	if (spi->mode & SPI_LSB_FIRST)
1001 		rspi->spcmd |= SPCMD_LSBF;
1002 
1003 	/* Configure slave signal to assert */
1004 	rspi->spcmd |= SPCMD_SSLA(spi->cs_gpiod ? rspi->ctlr->unused_native_cs
1005 						: spi->chip_select);
1006 
1007 	/* CMOS output mode and MOSI signal from previous transfer */
1008 	rspi->sppcr = 0;
1009 	if (spi->mode & SPI_LOOP)
1010 		rspi->sppcr |= SPPCR_SPLP;
1011 
1012 	rspi->ops->set_config_register(rspi, 8);
1013 
1014 	if (msg->spi->mode &
1015 	    (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)) {
1016 		/* Setup sequencer for messages with multiple transfer modes */
1017 		ret = qspi_setup_sequencer(rspi, msg);
1018 		if (ret < 0)
1019 			return ret;
1020 	}
1021 
1022 	/* Enable SPI function in master mode */
1023 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_SPE, RSPI_SPCR);
1024 	return 0;
1025 }
1026 
1027 static int rspi_unprepare_message(struct spi_controller *ctlr,
1028 				  struct spi_message *msg)
1029 {
1030 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
1031 
1032 	/* Disable SPI function */
1033 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_SPE, RSPI_SPCR);
1034 
1035 	/* Reset sequencer for Single SPI Transfers */
1036 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
1037 	rspi_write8(rspi, 0, RSPI_SPSCR);
1038 	return 0;
1039 }
1040 
1041 static irqreturn_t rspi_irq_mux(int irq, void *_sr)
1042 {
1043 	struct rspi_data *rspi = _sr;
1044 	u8 spsr;
1045 	irqreturn_t ret = IRQ_NONE;
1046 	u8 disable_irq = 0;
1047 
1048 	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
1049 	if (spsr & SPSR_SPRF)
1050 		disable_irq |= SPCR_SPRIE;
1051 	if (spsr & SPSR_SPTEF)
1052 		disable_irq |= SPCR_SPTIE;
1053 
1054 	if (disable_irq) {
1055 		ret = IRQ_HANDLED;
1056 		rspi_disable_irq(rspi, disable_irq);
1057 		wake_up(&rspi->wait);
1058 	}
1059 
1060 	return ret;
1061 }
1062 
1063 static irqreturn_t rspi_irq_rx(int irq, void *_sr)
1064 {
1065 	struct rspi_data *rspi = _sr;
1066 	u8 spsr;
1067 
1068 	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
1069 	if (spsr & SPSR_SPRF) {
1070 		rspi_disable_irq(rspi, SPCR_SPRIE);
1071 		wake_up(&rspi->wait);
1072 		return IRQ_HANDLED;
1073 	}
1074 
1075 	return 0;
1076 }
1077 
1078 static irqreturn_t rspi_irq_tx(int irq, void *_sr)
1079 {
1080 	struct rspi_data *rspi = _sr;
1081 	u8 spsr;
1082 
1083 	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
1084 	if (spsr & SPSR_SPTEF) {
1085 		rspi_disable_irq(rspi, SPCR_SPTIE);
1086 		wake_up(&rspi->wait);
1087 		return IRQ_HANDLED;
1088 	}
1089 
1090 	return 0;
1091 }
1092 
1093 static struct dma_chan *rspi_request_dma_chan(struct device *dev,
1094 					      enum dma_transfer_direction dir,
1095 					      unsigned int id,
1096 					      dma_addr_t port_addr)
1097 {
1098 	dma_cap_mask_t mask;
1099 	struct dma_chan *chan;
1100 	struct dma_slave_config cfg;
1101 	int ret;
1102 
1103 	dma_cap_zero(mask);
1104 	dma_cap_set(DMA_SLAVE, mask);
1105 
1106 	chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
1107 				(void *)(unsigned long)id, dev,
1108 				dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1109 	if (!chan) {
1110 		dev_warn(dev, "dma_request_slave_channel_compat failed\n");
1111 		return NULL;
1112 	}
1113 
1114 	memset(&cfg, 0, sizeof(cfg));
1115 	cfg.dst_addr = port_addr + RSPI_SPDR;
1116 	cfg.src_addr = port_addr + RSPI_SPDR;
1117 	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1118 	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1119 	cfg.direction = dir;
1120 
1121 	ret = dmaengine_slave_config(chan, &cfg);
1122 	if (ret) {
1123 		dev_warn(dev, "dmaengine_slave_config failed %d\n", ret);
1124 		dma_release_channel(chan);
1125 		return NULL;
1126 	}
1127 
1128 	return chan;
1129 }
1130 
1131 static int rspi_request_dma(struct device *dev, struct spi_controller *ctlr,
1132 			    const struct resource *res)
1133 {
1134 	const struct rspi_plat_data *rspi_pd = dev_get_platdata(dev);
1135 	unsigned int dma_tx_id, dma_rx_id;
1136 
1137 	if (dev->of_node) {
1138 		/* In the OF case we will get the slave IDs from the DT */
1139 		dma_tx_id = 0;
1140 		dma_rx_id = 0;
1141 	} else if (rspi_pd && rspi_pd->dma_tx_id && rspi_pd->dma_rx_id) {
1142 		dma_tx_id = rspi_pd->dma_tx_id;
1143 		dma_rx_id = rspi_pd->dma_rx_id;
1144 	} else {
1145 		/* The driver assumes no error. */
1146 		return 0;
1147 	}
1148 
1149 	ctlr->dma_tx = rspi_request_dma_chan(dev, DMA_MEM_TO_DEV, dma_tx_id,
1150 					     res->start);
1151 	if (!ctlr->dma_tx)
1152 		return -ENODEV;
1153 
1154 	ctlr->dma_rx = rspi_request_dma_chan(dev, DMA_DEV_TO_MEM, dma_rx_id,
1155 					     res->start);
1156 	if (!ctlr->dma_rx) {
1157 		dma_release_channel(ctlr->dma_tx);
1158 		ctlr->dma_tx = NULL;
1159 		return -ENODEV;
1160 	}
1161 
1162 	ctlr->can_dma = rspi_can_dma;
1163 	dev_info(dev, "DMA available");
1164 	return 0;
1165 }
1166 
1167 static void rspi_release_dma(struct spi_controller *ctlr)
1168 {
1169 	if (ctlr->dma_tx)
1170 		dma_release_channel(ctlr->dma_tx);
1171 	if (ctlr->dma_rx)
1172 		dma_release_channel(ctlr->dma_rx);
1173 }
1174 
1175 static int rspi_remove(struct platform_device *pdev)
1176 {
1177 	struct rspi_data *rspi = platform_get_drvdata(pdev);
1178 
1179 	rspi_release_dma(rspi->ctlr);
1180 	pm_runtime_disable(&pdev->dev);
1181 
1182 	return 0;
1183 }
1184 
1185 static const struct spi_ops rspi_ops = {
1186 	.set_config_register =	rspi_set_config_register,
1187 	.transfer_one =		rspi_transfer_one,
1188 	.min_div =		2,
1189 	.max_div =		4096,
1190 	.flags =		SPI_CONTROLLER_MUST_TX,
1191 	.fifo_size =		8,
1192 	.num_hw_ss =		2,
1193 };
1194 
1195 static const struct spi_ops rspi_rz_ops = {
1196 	.set_config_register =	rspi_rz_set_config_register,
1197 	.transfer_one =		rspi_rz_transfer_one,
1198 	.min_div =		2,
1199 	.max_div =		4096,
1200 	.flags =		SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
1201 	.fifo_size =		8,	/* 8 for TX, 32 for RX */
1202 	.num_hw_ss =		1,
1203 };
1204 
1205 static const struct spi_ops qspi_ops = {
1206 	.set_config_register =	qspi_set_config_register,
1207 	.transfer_one =		qspi_transfer_one,
1208 	.extra_mode_bits =	SPI_TX_DUAL | SPI_TX_QUAD |
1209 				SPI_RX_DUAL | SPI_RX_QUAD,
1210 	.min_div =		1,
1211 	.max_div =		4080,
1212 	.flags =		SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
1213 	.fifo_size =		32,
1214 	.num_hw_ss =		1,
1215 };
1216 
1217 #ifdef CONFIG_OF
1218 static const struct of_device_id rspi_of_match[] = {
1219 	/* RSPI on legacy SH */
1220 	{ .compatible = "renesas,rspi", .data = &rspi_ops },
1221 	/* RSPI on RZ/A1H */
1222 	{ .compatible = "renesas,rspi-rz", .data = &rspi_rz_ops },
1223 	/* QSPI on R-Car Gen2 */
1224 	{ .compatible = "renesas,qspi", .data = &qspi_ops },
1225 	{ /* sentinel */ }
1226 };
1227 
1228 MODULE_DEVICE_TABLE(of, rspi_of_match);
1229 
1230 static void rspi_reset_control_assert(void *data)
1231 {
1232 	reset_control_assert(data);
1233 }
1234 
1235 static int rspi_parse_dt(struct device *dev, struct spi_controller *ctlr)
1236 {
1237 	struct reset_control *rstc;
1238 	u32 num_cs;
1239 	int error;
1240 
1241 	/* Parse DT properties */
1242 	error = of_property_read_u32(dev->of_node, "num-cs", &num_cs);
1243 	if (error) {
1244 		dev_err(dev, "of_property_read_u32 num-cs failed %d\n", error);
1245 		return error;
1246 	}
1247 
1248 	ctlr->num_chipselect = num_cs;
1249 
1250 	rstc = devm_reset_control_get_optional_exclusive(dev, NULL);
1251 	if (IS_ERR(rstc))
1252 		return dev_err_probe(dev, PTR_ERR(rstc),
1253 					     "failed to get reset ctrl\n");
1254 
1255 	error = reset_control_deassert(rstc);
1256 	if (error) {
1257 		dev_err(dev, "failed to deassert reset %d\n", error);
1258 		return error;
1259 	}
1260 
1261 	error = devm_add_action_or_reset(dev, rspi_reset_control_assert, rstc);
1262 	if (error) {
1263 		dev_err(dev, "failed to register assert devm action, %d\n", error);
1264 		return error;
1265 	}
1266 
1267 	return 0;
1268 }
1269 #else
1270 #define rspi_of_match	NULL
1271 static inline int rspi_parse_dt(struct device *dev, struct spi_controller *ctlr)
1272 {
1273 	return -EINVAL;
1274 }
1275 #endif /* CONFIG_OF */
1276 
1277 static int rspi_request_irq(struct device *dev, unsigned int irq,
1278 			    irq_handler_t handler, const char *suffix,
1279 			    void *dev_id)
1280 {
1281 	const char *name = devm_kasprintf(dev, GFP_KERNEL, "%s:%s",
1282 					  dev_name(dev), suffix);
1283 	if (!name)
1284 		return -ENOMEM;
1285 
1286 	return devm_request_irq(dev, irq, handler, 0, name, dev_id);
1287 }
1288 
1289 static int rspi_probe(struct platform_device *pdev)
1290 {
1291 	struct resource *res;
1292 	struct spi_controller *ctlr;
1293 	struct rspi_data *rspi;
1294 	int ret;
1295 	const struct rspi_plat_data *rspi_pd;
1296 	const struct spi_ops *ops;
1297 	unsigned long clksrc;
1298 
1299 	ctlr = spi_alloc_master(&pdev->dev, sizeof(struct rspi_data));
1300 	if (ctlr == NULL)
1301 		return -ENOMEM;
1302 
1303 	ops = of_device_get_match_data(&pdev->dev);
1304 	if (ops) {
1305 		ret = rspi_parse_dt(&pdev->dev, ctlr);
1306 		if (ret)
1307 			goto error1;
1308 	} else {
1309 		ops = (struct spi_ops *)pdev->id_entry->driver_data;
1310 		rspi_pd = dev_get_platdata(&pdev->dev);
1311 		if (rspi_pd && rspi_pd->num_chipselect)
1312 			ctlr->num_chipselect = rspi_pd->num_chipselect;
1313 		else
1314 			ctlr->num_chipselect = 2; /* default */
1315 	}
1316 
1317 	rspi = spi_controller_get_devdata(ctlr);
1318 	platform_set_drvdata(pdev, rspi);
1319 	rspi->ops = ops;
1320 	rspi->ctlr = ctlr;
1321 
1322 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1323 	rspi->addr = devm_ioremap_resource(&pdev->dev, res);
1324 	if (IS_ERR(rspi->addr)) {
1325 		ret = PTR_ERR(rspi->addr);
1326 		goto error1;
1327 	}
1328 
1329 	rspi->clk = devm_clk_get(&pdev->dev, NULL);
1330 	if (IS_ERR(rspi->clk)) {
1331 		dev_err(&pdev->dev, "cannot get clock\n");
1332 		ret = PTR_ERR(rspi->clk);
1333 		goto error1;
1334 	}
1335 
1336 	rspi->pdev = pdev;
1337 	pm_runtime_enable(&pdev->dev);
1338 
1339 	init_waitqueue_head(&rspi->wait);
1340 	spin_lock_init(&rspi->lock);
1341 
1342 	ctlr->bus_num = pdev->id;
1343 	ctlr->setup = rspi_setup;
1344 	ctlr->auto_runtime_pm = true;
1345 	ctlr->transfer_one = ops->transfer_one;
1346 	ctlr->prepare_message = rspi_prepare_message;
1347 	ctlr->unprepare_message = rspi_unprepare_message;
1348 	ctlr->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST |
1349 			  SPI_LOOP | ops->extra_mode_bits;
1350 	clksrc = clk_get_rate(rspi->clk);
1351 	ctlr->min_speed_hz = DIV_ROUND_UP(clksrc, ops->max_div);
1352 	ctlr->max_speed_hz = DIV_ROUND_UP(clksrc, ops->min_div);
1353 	ctlr->flags = ops->flags;
1354 	ctlr->dev.of_node = pdev->dev.of_node;
1355 	ctlr->use_gpio_descriptors = true;
1356 	ctlr->max_native_cs = rspi->ops->num_hw_ss;
1357 
1358 	ret = platform_get_irq_byname_optional(pdev, "rx");
1359 	if (ret < 0) {
1360 		ret = platform_get_irq_byname_optional(pdev, "mux");
1361 		if (ret < 0)
1362 			ret = platform_get_irq(pdev, 0);
1363 		if (ret >= 0)
1364 			rspi->rx_irq = rspi->tx_irq = ret;
1365 	} else {
1366 		rspi->rx_irq = ret;
1367 		ret = platform_get_irq_byname(pdev, "tx");
1368 		if (ret >= 0)
1369 			rspi->tx_irq = ret;
1370 	}
1371 
1372 	if (rspi->rx_irq == rspi->tx_irq) {
1373 		/* Single multiplexed interrupt */
1374 		ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_mux,
1375 				       "mux", rspi);
1376 	} else {
1377 		/* Multi-interrupt mode, only SPRI and SPTI are used */
1378 		ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_rx,
1379 				       "rx", rspi);
1380 		if (!ret)
1381 			ret = rspi_request_irq(&pdev->dev, rspi->tx_irq,
1382 					       rspi_irq_tx, "tx", rspi);
1383 	}
1384 	if (ret < 0) {
1385 		dev_err(&pdev->dev, "request_irq error\n");
1386 		goto error2;
1387 	}
1388 
1389 	ret = rspi_request_dma(&pdev->dev, ctlr, res);
1390 	if (ret < 0)
1391 		dev_warn(&pdev->dev, "DMA not available, using PIO\n");
1392 
1393 	ret = devm_spi_register_controller(&pdev->dev, ctlr);
1394 	if (ret < 0) {
1395 		dev_err(&pdev->dev, "devm_spi_register_controller error.\n");
1396 		goto error3;
1397 	}
1398 
1399 	dev_info(&pdev->dev, "probed\n");
1400 
1401 	return 0;
1402 
1403 error3:
1404 	rspi_release_dma(ctlr);
1405 error2:
1406 	pm_runtime_disable(&pdev->dev);
1407 error1:
1408 	spi_controller_put(ctlr);
1409 
1410 	return ret;
1411 }
1412 
1413 static const struct platform_device_id spi_driver_ids[] = {
1414 	{ "rspi",	(kernel_ulong_t)&rspi_ops },
1415 	{},
1416 };
1417 
1418 MODULE_DEVICE_TABLE(platform, spi_driver_ids);
1419 
1420 #ifdef CONFIG_PM_SLEEP
1421 static int rspi_suspend(struct device *dev)
1422 {
1423 	struct rspi_data *rspi = dev_get_drvdata(dev);
1424 
1425 	return spi_controller_suspend(rspi->ctlr);
1426 }
1427 
1428 static int rspi_resume(struct device *dev)
1429 {
1430 	struct rspi_data *rspi = dev_get_drvdata(dev);
1431 
1432 	return spi_controller_resume(rspi->ctlr);
1433 }
1434 
1435 static SIMPLE_DEV_PM_OPS(rspi_pm_ops, rspi_suspend, rspi_resume);
1436 #define DEV_PM_OPS	&rspi_pm_ops
1437 #else
1438 #define DEV_PM_OPS	NULL
1439 #endif /* CONFIG_PM_SLEEP */
1440 
1441 static struct platform_driver rspi_driver = {
1442 	.probe =	rspi_probe,
1443 	.remove =	rspi_remove,
1444 	.id_table =	spi_driver_ids,
1445 	.driver		= {
1446 		.name = "renesas_spi",
1447 		.pm = DEV_PM_OPS,
1448 		.of_match_table = of_match_ptr(rspi_of_match),
1449 	},
1450 };
1451 module_platform_driver(rspi_driver);
1452 
1453 MODULE_DESCRIPTION("Renesas RSPI bus driver");
1454 MODULE_LICENSE("GPL v2");
1455 MODULE_AUTHOR("Yoshihiro Shimoda");
1456