xref: /linux/drivers/spi/spi-rspi.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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.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/spinlock.h>
28 
29 #define RSPI_SPCR		0x00	/* Control Register */
30 #define RSPI_SSLP		0x01	/* Slave Select Polarity Register */
31 #define RSPI_SPPCR		0x02	/* Pin Control Register */
32 #define RSPI_SPSR		0x03	/* Status Register */
33 #define RSPI_SPDR		0x04	/* Data Register */
34 #define RSPI_SPSCR		0x08	/* Sequence Control Register */
35 #define RSPI_SPSSR		0x09	/* Sequence Status Register */
36 #define RSPI_SPBR		0x0a	/* Bit Rate Register */
37 #define RSPI_SPDCR		0x0b	/* Data Control Register */
38 #define RSPI_SPCKD		0x0c	/* Clock Delay Register */
39 #define RSPI_SSLND		0x0d	/* Slave Select Negation Delay Register */
40 #define RSPI_SPND		0x0e	/* Next-Access Delay Register */
41 #define RSPI_SPCR2		0x0f	/* Control Register 2 (SH only) */
42 #define RSPI_SPCMD0		0x10	/* Command Register 0 */
43 #define RSPI_SPCMD1		0x12	/* Command Register 1 */
44 #define RSPI_SPCMD2		0x14	/* Command Register 2 */
45 #define RSPI_SPCMD3		0x16	/* Command Register 3 */
46 #define RSPI_SPCMD4		0x18	/* Command Register 4 */
47 #define RSPI_SPCMD5		0x1a	/* Command Register 5 */
48 #define RSPI_SPCMD6		0x1c	/* Command Register 6 */
49 #define RSPI_SPCMD7		0x1e	/* Command Register 7 */
50 #define RSPI_SPCMD(i)		(RSPI_SPCMD0 + (i) * 2)
51 #define RSPI_NUM_SPCMD		8
52 #define RSPI_RZ_NUM_SPCMD	4
53 #define QSPI_NUM_SPCMD		4
54 
55 /* RSPI on RZ only */
56 #define RSPI_SPBFCR		0x20	/* Buffer Control Register */
57 #define RSPI_SPBFDR		0x22	/* Buffer Data Count Setting Register */
58 
59 /* QSPI only */
60 #define QSPI_SPBFCR		0x18	/* Buffer Control Register */
61 #define QSPI_SPBDCR		0x1a	/* Buffer Data Count Register */
62 #define QSPI_SPBMUL0		0x1c	/* Transfer Data Length Multiplier Setting Register 0 */
63 #define QSPI_SPBMUL1		0x20	/* Transfer Data Length Multiplier Setting Register 1 */
64 #define QSPI_SPBMUL2		0x24	/* Transfer Data Length Multiplier Setting Register 2 */
65 #define QSPI_SPBMUL3		0x28	/* Transfer Data Length Multiplier Setting Register 3 */
66 #define QSPI_SPBMUL(i)		(QSPI_SPBMUL0 + (i) * 4)
67 
68 /* SPCR - Control Register */
69 #define SPCR_SPRIE		0x80	/* Receive Interrupt Enable */
70 #define SPCR_SPE		0x40	/* Function Enable */
71 #define SPCR_SPTIE		0x20	/* Transmit Interrupt Enable */
72 #define SPCR_SPEIE		0x10	/* Error Interrupt Enable */
73 #define SPCR_MSTR		0x08	/* Master/Slave Mode Select */
74 #define SPCR_MODFEN		0x04	/* Mode Fault Error Detection Enable */
75 /* RSPI on SH only */
76 #define SPCR_TXMD		0x02	/* TX Only Mode (vs. Full Duplex) */
77 #define SPCR_SPMS		0x01	/* 3-wire Mode (vs. 4-wire) */
78 /* QSPI on R-Car Gen2 only */
79 #define SPCR_WSWAP		0x02	/* Word Swap of read-data for DMAC */
80 #define SPCR_BSWAP		0x01	/* Byte Swap of read-data for DMAC */
81 
82 /* SSLP - Slave Select Polarity Register */
83 #define SSLP_SSLP(i)		BIT(i)	/* SSLi Signal Polarity Setting */
84 
85 /* SPPCR - Pin Control Register */
86 #define SPPCR_MOIFE		0x20	/* MOSI Idle Value Fixing Enable */
87 #define SPPCR_MOIFV		0x10	/* MOSI Idle Fixed Value */
88 #define SPPCR_SPOM		0x04
89 #define SPPCR_SPLP2		0x02	/* Loopback Mode 2 (non-inverting) */
90 #define SPPCR_SPLP		0x01	/* Loopback Mode (inverting) */
91 
92 #define SPPCR_IO3FV		0x04	/* Single-/Dual-SPI Mode IO3 Output Fixed Value */
93 #define SPPCR_IO2FV		0x04	/* Single-/Dual-SPI Mode IO2 Output Fixed Value */
94 
95 /* SPSR - Status Register */
96 #define SPSR_SPRF		0x80	/* Receive Buffer Full Flag */
97 #define SPSR_TEND		0x40	/* Transmit End */
98 #define SPSR_SPTEF		0x20	/* Transmit Buffer Empty Flag */
99 #define SPSR_PERF		0x08	/* Parity Error Flag */
100 #define SPSR_MODF		0x04	/* Mode Fault Error Flag */
101 #define SPSR_IDLNF		0x02	/* RSPI Idle Flag */
102 #define SPSR_OVRF		0x01	/* Overrun Error Flag (RSPI only) */
103 
104 /* SPSCR - Sequence Control Register */
105 #define SPSCR_SPSLN_MASK	0x07	/* Sequence Length Specification */
106 
107 /* SPSSR - Sequence Status Register */
108 #define SPSSR_SPECM_MASK	0x70	/* Command Error Mask */
109 #define SPSSR_SPCP_MASK		0x07	/* Command Pointer Mask */
110 
111 /* SPDCR - Data Control Register */
112 #define SPDCR_TXDMY		0x80	/* Dummy Data Transmission Enable */
113 #define SPDCR_SPLW1		0x40	/* Access Width Specification (RZ) */
114 #define SPDCR_SPLW0		0x20	/* Access Width Specification (RZ) */
115 #define SPDCR_SPLLWORD		(SPDCR_SPLW1 | SPDCR_SPLW0)
116 #define SPDCR_SPLWORD		SPDCR_SPLW1
117 #define SPDCR_SPLBYTE		SPDCR_SPLW0
118 #define SPDCR_SPLW		0x20	/* Access Width Specification (SH) */
119 #define SPDCR_SPRDTD		0x10	/* Receive Transmit Data Select (SH) */
120 #define SPDCR_SLSEL1		0x08
121 #define SPDCR_SLSEL0		0x04
122 #define SPDCR_SLSEL_MASK	0x0c	/* SSL1 Output Select (SH) */
123 #define SPDCR_SPFC1		0x02
124 #define SPDCR_SPFC0		0x01
125 #define SPDCR_SPFC_MASK		0x03	/* Frame Count Setting (1-4) (SH) */
126 
127 /* SPCKD - Clock Delay Register */
128 #define SPCKD_SCKDL_MASK	0x07	/* Clock Delay Setting (1-8) */
129 
130 /* SSLND - Slave Select Negation Delay Register */
131 #define SSLND_SLNDL_MASK	0x07	/* SSL Negation Delay Setting (1-8) */
132 
133 /* SPND - Next-Access Delay Register */
134 #define SPND_SPNDL_MASK		0x07	/* Next-Access Delay Setting (1-8) */
135 
136 /* SPCR2 - Control Register 2 */
137 #define SPCR2_PTE		0x08	/* Parity Self-Test Enable */
138 #define SPCR2_SPIE		0x04	/* Idle Interrupt Enable */
139 #define SPCR2_SPOE		0x02	/* Odd Parity Enable (vs. Even) */
140 #define SPCR2_SPPE		0x01	/* Parity Enable */
141 
142 /* SPCMDn - Command Registers */
143 #define SPCMD_SCKDEN		0x8000	/* Clock Delay Setting Enable */
144 #define SPCMD_SLNDEN		0x4000	/* SSL Negation Delay Setting Enable */
145 #define SPCMD_SPNDEN		0x2000	/* Next-Access Delay Enable */
146 #define SPCMD_LSBF		0x1000	/* LSB First */
147 #define SPCMD_SPB_MASK		0x0f00	/* Data Length Setting */
148 #define SPCMD_SPB_8_TO_16(bit)	(((bit - 1) << 8) & SPCMD_SPB_MASK)
149 #define SPCMD_SPB_8BIT		0x0000	/* QSPI only */
150 #define SPCMD_SPB_16BIT		0x0100
151 #define SPCMD_SPB_20BIT		0x0000
152 #define SPCMD_SPB_24BIT		0x0100
153 #define SPCMD_SPB_32BIT		0x0200
154 #define SPCMD_SSLKP		0x0080	/* SSL Signal Level Keeping */
155 #define SPCMD_SPIMOD_MASK	0x0060	/* SPI Operating Mode (QSPI only) */
156 #define SPCMD_SPIMOD1		0x0040
157 #define SPCMD_SPIMOD0		0x0020
158 #define SPCMD_SPIMOD_SINGLE	0
159 #define SPCMD_SPIMOD_DUAL	SPCMD_SPIMOD0
160 #define SPCMD_SPIMOD_QUAD	SPCMD_SPIMOD1
161 #define SPCMD_SPRW		0x0010	/* SPI Read/Write Access (Dual/Quad) */
162 #define SPCMD_SSLA(i)		((i) << 4)	/* SSL Assert Signal Setting */
163 #define SPCMD_BRDV_MASK		0x000c	/* Bit Rate Division Setting */
164 #define SPCMD_BRDV(brdv)	((brdv) << 2)
165 #define SPCMD_CPOL		0x0002	/* Clock Polarity Setting */
166 #define SPCMD_CPHA		0x0001	/* Clock Phase Setting */
167 
168 /* SPBFCR - Buffer Control Register */
169 #define SPBFCR_TXRST		0x80	/* Transmit Buffer Data Reset */
170 #define SPBFCR_RXRST		0x40	/* Receive Buffer Data Reset */
171 #define SPBFCR_TXTRG_MASK	0x30	/* Transmit Buffer Data Triggering Number */
172 #define SPBFCR_RXTRG_MASK	0x07	/* Receive Buffer Data Triggering Number */
173 /* QSPI on R-Car Gen2 */
174 #define SPBFCR_TXTRG_1B		0x00	/* 31 bytes (1 byte available) */
175 #define SPBFCR_TXTRG_32B	0x30	/* 0 byte (32 bytes available) */
176 #define SPBFCR_RXTRG_1B		0x00	/* 1 byte (31 bytes available) */
177 #define SPBFCR_RXTRG_32B	0x07	/* 32 bytes (0 byte available) */
178 
179 #define QSPI_BUFFER_SIZE        32u
180 
181 struct rspi_data {
182 	void __iomem *addr;
183 	u32 speed_hz;
184 	struct spi_controller *ctlr;
185 	struct platform_device *pdev;
186 	wait_queue_head_t wait;
187 	spinlock_t lock;		/* Protects RMW-access to RSPI_SSLP */
188 	struct clk *clk;
189 	u16 spcmd;
190 	u8 spsr;
191 	u8 sppcr;
192 	int rx_irq, tx_irq;
193 	const struct spi_ops *ops;
194 
195 	unsigned dma_callbacked:1;
196 	unsigned byte_access:1;
197 };
198 
199 static void rspi_write8(const struct rspi_data *rspi, u8 data, u16 offset)
200 {
201 	iowrite8(data, rspi->addr + offset);
202 }
203 
204 static void rspi_write16(const struct rspi_data *rspi, u16 data, u16 offset)
205 {
206 	iowrite16(data, rspi->addr + offset);
207 }
208 
209 static void rspi_write32(const struct rspi_data *rspi, u32 data, u16 offset)
210 {
211 	iowrite32(data, rspi->addr + offset);
212 }
213 
214 static u8 rspi_read8(const struct rspi_data *rspi, u16 offset)
215 {
216 	return ioread8(rspi->addr + offset);
217 }
218 
219 static u16 rspi_read16(const struct rspi_data *rspi, u16 offset)
220 {
221 	return ioread16(rspi->addr + offset);
222 }
223 
224 static void rspi_write_data(const struct rspi_data *rspi, u16 data)
225 {
226 	if (rspi->byte_access)
227 		rspi_write8(rspi, data, RSPI_SPDR);
228 	else /* 16 bit */
229 		rspi_write16(rspi, data, RSPI_SPDR);
230 }
231 
232 static u16 rspi_read_data(const struct rspi_data *rspi)
233 {
234 	if (rspi->byte_access)
235 		return rspi_read8(rspi, RSPI_SPDR);
236 	else /* 16 bit */
237 		return rspi_read16(rspi, RSPI_SPDR);
238 }
239 
240 /* optional functions */
241 struct spi_ops {
242 	int (*set_config_register)(struct rspi_data *rspi, int access_size);
243 	int (*transfer_one)(struct spi_controller *ctlr,
244 			    struct spi_device *spi, struct spi_transfer *xfer);
245 	u16 extra_mode_bits;
246 	u16 min_div;
247 	u16 max_div;
248 	u16 flags;
249 	u16 fifo_size;
250 	u8 num_hw_ss;
251 };
252 
253 static void rspi_set_rate(struct rspi_data *rspi)
254 {
255 	unsigned long clksrc;
256 	int brdv = 0, spbr;
257 
258 	clksrc = clk_get_rate(rspi->clk);
259 	spbr = DIV_ROUND_UP(clksrc, 2 * rspi->speed_hz) - 1;
260 	while (spbr > 255 && brdv < 3) {
261 		brdv++;
262 		spbr = DIV_ROUND_UP(spbr + 1, 2) - 1;
263 	}
264 
265 	rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
266 	rspi->spcmd |= SPCMD_BRDV(brdv);
267 	rspi->speed_hz = DIV_ROUND_UP(clksrc, (2U << brdv) * (spbr + 1));
268 }
269 
270 /*
271  * functions for RSPI on legacy SH
272  */
273 static int rspi_set_config_register(struct rspi_data *rspi, int access_size)
274 {
275 	/* Sets output mode, MOSI signal, and (optionally) loopback */
276 	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
277 
278 	/* Sets transfer bit rate */
279 	rspi_set_rate(rspi);
280 
281 	/* Disable dummy transmission, set 16-bit word access, 1 frame */
282 	rspi_write8(rspi, 0, RSPI_SPDCR);
283 	rspi->byte_access = 0;
284 
285 	/* Sets RSPCK, SSL, next-access delay value */
286 	rspi_write8(rspi, 0x00, RSPI_SPCKD);
287 	rspi_write8(rspi, 0x00, RSPI_SSLND);
288 	rspi_write8(rspi, 0x00, RSPI_SPND);
289 
290 	/* Sets parity, interrupt mask */
291 	rspi_write8(rspi, 0x00, RSPI_SPCR2);
292 
293 	/* Resets sequencer */
294 	rspi_write8(rspi, 0, RSPI_SPSCR);
295 	rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
296 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
297 
298 	/* Sets RSPI mode */
299 	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
300 
301 	return 0;
302 }
303 
304 /*
305  * functions for RSPI on RZ
306  */
307 static int rspi_rz_set_config_register(struct rspi_data *rspi, int access_size)
308 {
309 	/* Sets output mode, MOSI signal, and (optionally) loopback */
310 	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
311 
312 	/* Sets transfer bit rate */
313 	rspi_set_rate(rspi);
314 
315 	/* Disable dummy transmission, set byte access */
316 	rspi_write8(rspi, SPDCR_SPLBYTE, RSPI_SPDCR);
317 	rspi->byte_access = 1;
318 
319 	/* Sets RSPCK, SSL, next-access delay value */
320 	rspi_write8(rspi, 0x00, RSPI_SPCKD);
321 	rspi_write8(rspi, 0x00, RSPI_SSLND);
322 	rspi_write8(rspi, 0x00, RSPI_SPND);
323 
324 	/* Resets sequencer */
325 	rspi_write8(rspi, 0, RSPI_SPSCR);
326 	rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
327 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
328 
329 	/* Sets RSPI mode */
330 	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
331 
332 	return 0;
333 }
334 
335 /*
336  * functions for QSPI
337  */
338 static int qspi_set_config_register(struct rspi_data *rspi, int access_size)
339 {
340 	unsigned long clksrc;
341 	int brdv = 0, spbr;
342 
343 	/* Sets output mode, MOSI signal, and (optionally) loopback */
344 	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
345 
346 	/* Sets transfer bit rate */
347 	clksrc = clk_get_rate(rspi->clk);
348 	if (rspi->speed_hz >= clksrc) {
349 		spbr = 0;
350 		rspi->speed_hz = clksrc;
351 	} else {
352 		spbr = DIV_ROUND_UP(clksrc, 2 * rspi->speed_hz);
353 		while (spbr > 255 && brdv < 3) {
354 			brdv++;
355 			spbr = DIV_ROUND_UP(spbr, 2);
356 		}
357 		spbr = clamp(spbr, 0, 255);
358 		rspi->speed_hz = DIV_ROUND_UP(clksrc, (2U << brdv) * spbr);
359 	}
360 	rspi_write8(rspi, spbr, RSPI_SPBR);
361 	rspi->spcmd |= SPCMD_BRDV(brdv);
362 
363 	/* Disable dummy transmission, set byte access */
364 	rspi_write8(rspi, 0, RSPI_SPDCR);
365 	rspi->byte_access = 1;
366 
367 	/* Sets RSPCK, SSL, next-access delay value */
368 	rspi_write8(rspi, 0x00, RSPI_SPCKD);
369 	rspi_write8(rspi, 0x00, RSPI_SSLND);
370 	rspi_write8(rspi, 0x00, RSPI_SPND);
371 
372 	/* Data Length Setting */
373 	if (access_size == 8)
374 		rspi->spcmd |= SPCMD_SPB_8BIT;
375 	else if (access_size == 16)
376 		rspi->spcmd |= SPCMD_SPB_16BIT;
377 	else
378 		rspi->spcmd |= SPCMD_SPB_32BIT;
379 
380 	rspi->spcmd |= SPCMD_SCKDEN | SPCMD_SLNDEN | SPCMD_SPNDEN;
381 
382 	/* Resets transfer data length */
383 	rspi_write32(rspi, 0, QSPI_SPBMUL0);
384 
385 	/* Resets transmit and receive buffer */
386 	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
387 	/* Sets buffer to allow normal operation */
388 	rspi_write8(rspi, 0x00, QSPI_SPBFCR);
389 
390 	/* Resets sequencer */
391 	rspi_write8(rspi, 0, RSPI_SPSCR);
392 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
393 
394 	/* Sets RSPI mode */
395 	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
396 
397 	return 0;
398 }
399 
400 static void qspi_update(const struct rspi_data *rspi, u8 mask, u8 val, u8 reg)
401 {
402 	u8 data;
403 
404 	data = rspi_read8(rspi, reg);
405 	data &= ~mask;
406 	data |= (val & mask);
407 	rspi_write8(rspi, data, reg);
408 }
409 
410 static unsigned int qspi_set_send_trigger(struct rspi_data *rspi,
411 					  unsigned int len)
412 {
413 	unsigned int n;
414 
415 	n = min(len, QSPI_BUFFER_SIZE);
416 
417 	if (len >= QSPI_BUFFER_SIZE) {
418 		/* sets triggering number to 32 bytes */
419 		qspi_update(rspi, SPBFCR_TXTRG_MASK,
420 			     SPBFCR_TXTRG_32B, QSPI_SPBFCR);
421 	} else {
422 		/* sets triggering number to 1 byte */
423 		qspi_update(rspi, SPBFCR_TXTRG_MASK,
424 			     SPBFCR_TXTRG_1B, QSPI_SPBFCR);
425 	}
426 
427 	return n;
428 }
429 
430 static int qspi_set_receive_trigger(struct rspi_data *rspi, unsigned int len)
431 {
432 	unsigned int n;
433 
434 	n = min(len, QSPI_BUFFER_SIZE);
435 
436 	if (len >= QSPI_BUFFER_SIZE) {
437 		/* sets triggering number to 32 bytes */
438 		qspi_update(rspi, SPBFCR_RXTRG_MASK,
439 			     SPBFCR_RXTRG_32B, QSPI_SPBFCR);
440 	} else {
441 		/* sets triggering number to 1 byte */
442 		qspi_update(rspi, SPBFCR_RXTRG_MASK,
443 			     SPBFCR_RXTRG_1B, QSPI_SPBFCR);
444 	}
445 	return n;
446 }
447 
448 static void rspi_enable_irq(const struct rspi_data *rspi, u8 enable)
449 {
450 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | enable, RSPI_SPCR);
451 }
452 
453 static void rspi_disable_irq(const struct rspi_data *rspi, u8 disable)
454 {
455 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~disable, RSPI_SPCR);
456 }
457 
458 static int rspi_wait_for_interrupt(struct rspi_data *rspi, u8 wait_mask,
459 				   u8 enable_bit)
460 {
461 	int ret;
462 
463 	rspi->spsr = rspi_read8(rspi, RSPI_SPSR);
464 	if (rspi->spsr & wait_mask)
465 		return 0;
466 
467 	rspi_enable_irq(rspi, enable_bit);
468 	ret = wait_event_timeout(rspi->wait, rspi->spsr & wait_mask, HZ);
469 	if (ret == 0 && !(rspi->spsr & wait_mask))
470 		return -ETIMEDOUT;
471 
472 	return 0;
473 }
474 
475 static inline int rspi_wait_for_tx_empty(struct rspi_data *rspi)
476 {
477 	return rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
478 }
479 
480 static inline int rspi_wait_for_rx_full(struct rspi_data *rspi)
481 {
482 	return rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE);
483 }
484 
485 static int rspi_data_out(struct rspi_data *rspi, u8 data)
486 {
487 	int error = rspi_wait_for_tx_empty(rspi);
488 	if (error < 0) {
489 		dev_err(&rspi->ctlr->dev, "transmit timeout\n");
490 		return error;
491 	}
492 	rspi_write_data(rspi, data);
493 	return 0;
494 }
495 
496 static int rspi_data_in(struct rspi_data *rspi)
497 {
498 	int error;
499 	u8 data;
500 
501 	error = rspi_wait_for_rx_full(rspi);
502 	if (error < 0) {
503 		dev_err(&rspi->ctlr->dev, "receive timeout\n");
504 		return error;
505 	}
506 	data = rspi_read_data(rspi);
507 	return data;
508 }
509 
510 static int rspi_pio_transfer(struct rspi_data *rspi, const u8 *tx, u8 *rx,
511 			     unsigned int n)
512 {
513 	while (n-- > 0) {
514 		if (tx) {
515 			int ret = rspi_data_out(rspi, *tx++);
516 			if (ret < 0)
517 				return ret;
518 		}
519 		if (rx) {
520 			int ret = rspi_data_in(rspi);
521 			if (ret < 0)
522 				return ret;
523 			*rx++ = ret;
524 		}
525 	}
526 
527 	return 0;
528 }
529 
530 static void rspi_dma_complete(void *arg)
531 {
532 	struct rspi_data *rspi = arg;
533 
534 	rspi->dma_callbacked = 1;
535 	wake_up_interruptible(&rspi->wait);
536 }
537 
538 static int rspi_dma_transfer(struct rspi_data *rspi, struct sg_table *tx,
539 			     struct sg_table *rx)
540 {
541 	struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
542 	u8 irq_mask = 0;
543 	unsigned int other_irq = 0;
544 	dma_cookie_t cookie;
545 	int ret;
546 
547 	/* First prepare and submit the DMA request(s), as this may fail */
548 	if (rx) {
549 		desc_rx = dmaengine_prep_slave_sg(rspi->ctlr->dma_rx, rx->sgl,
550 					rx->nents, DMA_DEV_TO_MEM,
551 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
552 		if (!desc_rx) {
553 			ret = -EAGAIN;
554 			goto no_dma_rx;
555 		}
556 
557 		desc_rx->callback = rspi_dma_complete;
558 		desc_rx->callback_param = rspi;
559 		cookie = dmaengine_submit(desc_rx);
560 		if (dma_submit_error(cookie)) {
561 			ret = cookie;
562 			goto no_dma_rx;
563 		}
564 
565 		irq_mask |= SPCR_SPRIE;
566 	}
567 
568 	if (tx) {
569 		desc_tx = dmaengine_prep_slave_sg(rspi->ctlr->dma_tx, tx->sgl,
570 					tx->nents, DMA_MEM_TO_DEV,
571 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
572 		if (!desc_tx) {
573 			ret = -EAGAIN;
574 			goto no_dma_tx;
575 		}
576 
577 		if (rx) {
578 			/* No callback */
579 			desc_tx->callback = NULL;
580 		} else {
581 			desc_tx->callback = rspi_dma_complete;
582 			desc_tx->callback_param = rspi;
583 		}
584 		cookie = dmaengine_submit(desc_tx);
585 		if (dma_submit_error(cookie)) {
586 			ret = cookie;
587 			goto no_dma_tx;
588 		}
589 
590 		irq_mask |= SPCR_SPTIE;
591 	}
592 
593 	/*
594 	 * DMAC needs SPxIE, but if SPxIE is set, the IRQ routine will be
595 	 * called. So, this driver disables the IRQ while DMA transfer.
596 	 */
597 	if (tx)
598 		disable_irq(other_irq = rspi->tx_irq);
599 	if (rx && rspi->rx_irq != other_irq)
600 		disable_irq(rspi->rx_irq);
601 
602 	rspi_enable_irq(rspi, irq_mask);
603 	rspi->dma_callbacked = 0;
604 
605 	/* Now start DMA */
606 	if (rx)
607 		dma_async_issue_pending(rspi->ctlr->dma_rx);
608 	if (tx)
609 		dma_async_issue_pending(rspi->ctlr->dma_tx);
610 
611 	ret = wait_event_interruptible_timeout(rspi->wait,
612 					       rspi->dma_callbacked, HZ);
613 	if (ret > 0 && rspi->dma_callbacked) {
614 		ret = 0;
615 		if (tx)
616 			dmaengine_synchronize(rspi->ctlr->dma_tx);
617 		if (rx)
618 			dmaengine_synchronize(rspi->ctlr->dma_rx);
619 	} else {
620 		if (!ret) {
621 			dev_err(&rspi->ctlr->dev, "DMA timeout\n");
622 			ret = -ETIMEDOUT;
623 		}
624 		if (tx)
625 			dmaengine_terminate_sync(rspi->ctlr->dma_tx);
626 		if (rx)
627 			dmaengine_terminate_sync(rspi->ctlr->dma_rx);
628 	}
629 
630 	rspi_disable_irq(rspi, irq_mask);
631 
632 	if (tx)
633 		enable_irq(rspi->tx_irq);
634 	if (rx && rspi->rx_irq != other_irq)
635 		enable_irq(rspi->rx_irq);
636 
637 	return ret;
638 
639 no_dma_tx:
640 	if (rx)
641 		dmaengine_terminate_sync(rspi->ctlr->dma_rx);
642 no_dma_rx:
643 	if (ret == -EAGAIN) {
644 		dev_warn_once(&rspi->ctlr->dev,
645 			      "DMA not available, falling back to PIO\n");
646 	}
647 	return ret;
648 }
649 
650 static void rspi_receive_init(const struct rspi_data *rspi)
651 {
652 	u8 spsr;
653 
654 	spsr = rspi_read8(rspi, RSPI_SPSR);
655 	if (spsr & SPSR_SPRF)
656 		rspi_read_data(rspi);	/* dummy read */
657 	if (spsr & SPSR_OVRF)
658 		rspi_write8(rspi, rspi_read8(rspi, RSPI_SPSR) & ~SPSR_OVRF,
659 			    RSPI_SPSR);
660 }
661 
662 static void rspi_rz_receive_init(const struct rspi_data *rspi)
663 {
664 	rspi_receive_init(rspi);
665 	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, RSPI_SPBFCR);
666 	rspi_write8(rspi, 0, RSPI_SPBFCR);
667 }
668 
669 static void qspi_receive_init(const struct rspi_data *rspi)
670 {
671 	u8 spsr;
672 
673 	spsr = rspi_read8(rspi, RSPI_SPSR);
674 	if (spsr & SPSR_SPRF)
675 		rspi_read_data(rspi);   /* dummy read */
676 	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
677 	rspi_write8(rspi, 0, QSPI_SPBFCR);
678 }
679 
680 static bool __rspi_can_dma(const struct rspi_data *rspi,
681 			   const struct spi_transfer *xfer)
682 {
683 	return xfer->len > rspi->ops->fifo_size;
684 }
685 
686 static bool rspi_can_dma(struct spi_controller *ctlr, struct spi_device *spi,
687 			 struct spi_transfer *xfer)
688 {
689 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
690 
691 	return __rspi_can_dma(rspi, xfer);
692 }
693 
694 static int rspi_dma_check_then_transfer(struct rspi_data *rspi,
695 					 struct spi_transfer *xfer)
696 {
697 	if (!rspi->ctlr->can_dma || !__rspi_can_dma(rspi, xfer))
698 		return -EAGAIN;
699 
700 	/* rx_buf can be NULL on RSPI on SH in TX-only Mode */
701 	return rspi_dma_transfer(rspi, &xfer->tx_sg,
702 				xfer->rx_buf ? &xfer->rx_sg : NULL);
703 }
704 
705 static int rspi_common_transfer(struct rspi_data *rspi,
706 				struct spi_transfer *xfer)
707 {
708 	int ret;
709 
710 	xfer->effective_speed_hz = rspi->speed_hz;
711 
712 	ret = rspi_dma_check_then_transfer(rspi, xfer);
713 	if (ret != -EAGAIN)
714 		return ret;
715 
716 	ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len);
717 	if (ret < 0)
718 		return ret;
719 
720 	/* Wait for the last transmission */
721 	rspi_wait_for_tx_empty(rspi);
722 
723 	return 0;
724 }
725 
726 static int rspi_transfer_one(struct spi_controller *ctlr,
727 			     struct spi_device *spi, struct spi_transfer *xfer)
728 {
729 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
730 	u8 spcr;
731 
732 	spcr = rspi_read8(rspi, RSPI_SPCR);
733 	if (xfer->rx_buf) {
734 		rspi_receive_init(rspi);
735 		spcr &= ~SPCR_TXMD;
736 	} else {
737 		spcr |= SPCR_TXMD;
738 	}
739 	rspi_write8(rspi, spcr, RSPI_SPCR);
740 
741 	return rspi_common_transfer(rspi, xfer);
742 }
743 
744 static int rspi_rz_transfer_one(struct spi_controller *ctlr,
745 				struct spi_device *spi,
746 				struct spi_transfer *xfer)
747 {
748 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
749 
750 	rspi_rz_receive_init(rspi);
751 
752 	return rspi_common_transfer(rspi, xfer);
753 }
754 
755 static int qspi_trigger_transfer_out_in(struct rspi_data *rspi, const u8 *tx,
756 					u8 *rx, unsigned int len)
757 {
758 	unsigned int i, n;
759 	int ret;
760 
761 	while (len > 0) {
762 		n = qspi_set_send_trigger(rspi, len);
763 		qspi_set_receive_trigger(rspi, len);
764 		ret = rspi_wait_for_tx_empty(rspi);
765 		if (ret < 0) {
766 			dev_err(&rspi->ctlr->dev, "transmit timeout\n");
767 			return ret;
768 		}
769 		for (i = 0; i < n; i++)
770 			rspi_write_data(rspi, *tx++);
771 
772 		ret = rspi_wait_for_rx_full(rspi);
773 		if (ret < 0) {
774 			dev_err(&rspi->ctlr->dev, "receive timeout\n");
775 			return ret;
776 		}
777 		for (i = 0; i < n; i++)
778 			*rx++ = rspi_read_data(rspi);
779 
780 		len -= n;
781 	}
782 
783 	return 0;
784 }
785 
786 static int qspi_transfer_out_in(struct rspi_data *rspi,
787 				struct spi_transfer *xfer)
788 {
789 	int ret;
790 
791 	qspi_receive_init(rspi);
792 
793 	ret = rspi_dma_check_then_transfer(rspi, xfer);
794 	if (ret != -EAGAIN)
795 		return ret;
796 
797 	return qspi_trigger_transfer_out_in(rspi, xfer->tx_buf,
798 					    xfer->rx_buf, xfer->len);
799 }
800 
801 static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer)
802 {
803 	const u8 *tx = xfer->tx_buf;
804 	unsigned int n = xfer->len;
805 	unsigned int i, len;
806 	int ret;
807 
808 	if (rspi->ctlr->can_dma && __rspi_can_dma(rspi, xfer)) {
809 		ret = rspi_dma_transfer(rspi, &xfer->tx_sg, NULL);
810 		if (ret != -EAGAIN)
811 			return ret;
812 	}
813 
814 	while (n > 0) {
815 		len = qspi_set_send_trigger(rspi, n);
816 		ret = rspi_wait_for_tx_empty(rspi);
817 		if (ret < 0) {
818 			dev_err(&rspi->ctlr->dev, "transmit timeout\n");
819 			return ret;
820 		}
821 		for (i = 0; i < len; i++)
822 			rspi_write_data(rspi, *tx++);
823 
824 		n -= len;
825 	}
826 
827 	/* Wait for the last transmission */
828 	rspi_wait_for_tx_empty(rspi);
829 
830 	return 0;
831 }
832 
833 static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer)
834 {
835 	u8 *rx = xfer->rx_buf;
836 	unsigned int n = xfer->len;
837 	unsigned int i, len;
838 	int ret;
839 
840 	if (rspi->ctlr->can_dma && __rspi_can_dma(rspi, xfer)) {
841 		ret = rspi_dma_transfer(rspi, NULL, &xfer->rx_sg);
842 		if (ret != -EAGAIN)
843 			return ret;
844 	}
845 
846 	while (n > 0) {
847 		len = qspi_set_receive_trigger(rspi, n);
848 		ret = rspi_wait_for_rx_full(rspi);
849 		if (ret < 0) {
850 			dev_err(&rspi->ctlr->dev, "receive timeout\n");
851 			return ret;
852 		}
853 		for (i = 0; i < len; i++)
854 			*rx++ = rspi_read_data(rspi);
855 
856 		n -= len;
857 	}
858 
859 	return 0;
860 }
861 
862 static int qspi_transfer_one(struct spi_controller *ctlr,
863 			     struct spi_device *spi, struct spi_transfer *xfer)
864 {
865 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
866 
867 	xfer->effective_speed_hz = rspi->speed_hz;
868 	if (spi->mode & SPI_LOOP) {
869 		return qspi_transfer_out_in(rspi, xfer);
870 	} else if (xfer->tx_nbits > SPI_NBITS_SINGLE) {
871 		/* Quad or Dual SPI Write */
872 		return qspi_transfer_out(rspi, xfer);
873 	} else if (xfer->rx_nbits > SPI_NBITS_SINGLE) {
874 		/* Quad or Dual SPI Read */
875 		return qspi_transfer_in(rspi, xfer);
876 	} else {
877 		/* Single SPI Transfer */
878 		return qspi_transfer_out_in(rspi, xfer);
879 	}
880 }
881 
882 static u16 qspi_transfer_mode(const struct spi_transfer *xfer)
883 {
884 	if (xfer->tx_buf)
885 		switch (xfer->tx_nbits) {
886 		case SPI_NBITS_QUAD:
887 			return SPCMD_SPIMOD_QUAD;
888 		case SPI_NBITS_DUAL:
889 			return SPCMD_SPIMOD_DUAL;
890 		default:
891 			return 0;
892 		}
893 	if (xfer->rx_buf)
894 		switch (xfer->rx_nbits) {
895 		case SPI_NBITS_QUAD:
896 			return SPCMD_SPIMOD_QUAD | SPCMD_SPRW;
897 		case SPI_NBITS_DUAL:
898 			return SPCMD_SPIMOD_DUAL | SPCMD_SPRW;
899 		default:
900 			return 0;
901 		}
902 
903 	return 0;
904 }
905 
906 static int qspi_setup_sequencer(struct rspi_data *rspi,
907 				const struct spi_message *msg)
908 {
909 	const struct spi_transfer *xfer;
910 	unsigned int i = 0, len = 0;
911 	u16 current_mode = 0xffff, mode;
912 
913 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
914 		mode = qspi_transfer_mode(xfer);
915 		if (mode == current_mode) {
916 			len += xfer->len;
917 			continue;
918 		}
919 
920 		/* Transfer mode change */
921 		if (i) {
922 			/* Set transfer data length of previous transfer */
923 			rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
924 		}
925 
926 		if (i >= QSPI_NUM_SPCMD) {
927 			dev_err(&msg->spi->dev,
928 				"Too many different transfer modes");
929 			return -EINVAL;
930 		}
931 
932 		/* Program transfer mode for this transfer */
933 		rspi_write16(rspi, rspi->spcmd | mode, RSPI_SPCMD(i));
934 		current_mode = mode;
935 		len = xfer->len;
936 		i++;
937 	}
938 	if (i) {
939 		/* Set final transfer data length and sequence length */
940 		rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
941 		rspi_write8(rspi, i - 1, RSPI_SPSCR);
942 	}
943 
944 	return 0;
945 }
946 
947 static int rspi_setup(struct spi_device *spi)
948 {
949 	struct rspi_data *rspi = spi_controller_get_devdata(spi->controller);
950 	u8 sslp;
951 
952 	if (spi_get_csgpiod(spi, 0))
953 		return 0;
954 
955 	pm_runtime_get_sync(&rspi->pdev->dev);
956 	spin_lock_irq(&rspi->lock);
957 
958 	sslp = rspi_read8(rspi, RSPI_SSLP);
959 	if (spi->mode & SPI_CS_HIGH)
960 		sslp |= SSLP_SSLP(spi_get_chipselect(spi, 0));
961 	else
962 		sslp &= ~SSLP_SSLP(spi_get_chipselect(spi, 0));
963 	rspi_write8(rspi, sslp, RSPI_SSLP);
964 
965 	spin_unlock_irq(&rspi->lock);
966 	pm_runtime_put(&rspi->pdev->dev);
967 	return 0;
968 }
969 
970 static int rspi_prepare_message(struct spi_controller *ctlr,
971 				struct spi_message *msg)
972 {
973 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
974 	struct spi_device *spi = msg->spi;
975 	const struct spi_transfer *xfer;
976 	int ret;
977 
978 	/*
979 	 * As the Bit Rate Register must not be changed while the device is
980 	 * active, all transfers in a message must use the same bit rate.
981 	 * In theory, the sequencer could be enabled, and each Command Register
982 	 * could divide the base bit rate by a different value.
983 	 * However, most RSPI variants do not have Transfer Data Length
984 	 * Multiplier Setting Registers, so each sequence step would be limited
985 	 * to a single word, making this feature unsuitable for large
986 	 * transfers, which would gain most from it.
987 	 */
988 	rspi->speed_hz = spi->max_speed_hz;
989 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
990 		if (xfer->speed_hz < rspi->speed_hz)
991 			rspi->speed_hz = xfer->speed_hz;
992 	}
993 
994 	rspi->spcmd = SPCMD_SSLKP;
995 	if (spi->mode & SPI_CPOL)
996 		rspi->spcmd |= SPCMD_CPOL;
997 	if (spi->mode & SPI_CPHA)
998 		rspi->spcmd |= SPCMD_CPHA;
999 	if (spi->mode & SPI_LSB_FIRST)
1000 		rspi->spcmd |= SPCMD_LSBF;
1001 
1002 	/* Configure slave signal to assert */
1003 	rspi->spcmd |= SPCMD_SSLA(spi_get_csgpiod(spi, 0) ? rspi->ctlr->unused_native_cs
1004 						: spi_get_chipselect(spi, 0));
1005 
1006 	/* CMOS output mode and MOSI signal from previous transfer */
1007 	rspi->sppcr = 0;
1008 	if (spi->mode & SPI_LOOP)
1009 		rspi->sppcr |= SPPCR_SPLP;
1010 
1011 	rspi->ops->set_config_register(rspi, 8);
1012 
1013 	if (msg->spi->mode &
1014 	    (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)) {
1015 		/* Setup sequencer for messages with multiple transfer modes */
1016 		ret = qspi_setup_sequencer(rspi, msg);
1017 		if (ret < 0)
1018 			return ret;
1019 	}
1020 
1021 	/* Enable SPI function in master mode */
1022 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_SPE, RSPI_SPCR);
1023 	return 0;
1024 }
1025 
1026 static int rspi_unprepare_message(struct spi_controller *ctlr,
1027 				  struct spi_message *msg)
1028 {
1029 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
1030 
1031 	/* Disable SPI function */
1032 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_SPE, RSPI_SPCR);
1033 
1034 	/* Reset sequencer for Single SPI Transfers */
1035 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
1036 	rspi_write8(rspi, 0, RSPI_SPSCR);
1037 	return 0;
1038 }
1039 
1040 static irqreturn_t rspi_irq_mux(int irq, void *_sr)
1041 {
1042 	struct rspi_data *rspi = _sr;
1043 	u8 spsr;
1044 	irqreturn_t ret = IRQ_NONE;
1045 	u8 disable_irq = 0;
1046 
1047 	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
1048 	if (spsr & SPSR_SPRF)
1049 		disable_irq |= SPCR_SPRIE;
1050 	if (spsr & SPSR_SPTEF)
1051 		disable_irq |= SPCR_SPTIE;
1052 
1053 	if (disable_irq) {
1054 		ret = IRQ_HANDLED;
1055 		rspi_disable_irq(rspi, disable_irq);
1056 		wake_up(&rspi->wait);
1057 	}
1058 
1059 	return ret;
1060 }
1061 
1062 static irqreturn_t rspi_irq_rx(int irq, void *_sr)
1063 {
1064 	struct rspi_data *rspi = _sr;
1065 	u8 spsr;
1066 
1067 	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
1068 	if (spsr & SPSR_SPRF) {
1069 		rspi_disable_irq(rspi, SPCR_SPRIE);
1070 		wake_up(&rspi->wait);
1071 		return IRQ_HANDLED;
1072 	}
1073 
1074 	return 0;
1075 }
1076 
1077 static irqreturn_t rspi_irq_tx(int irq, void *_sr)
1078 {
1079 	struct rspi_data *rspi = _sr;
1080 	u8 spsr;
1081 
1082 	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
1083 	if (spsr & SPSR_SPTEF) {
1084 		rspi_disable_irq(rspi, SPCR_SPTIE);
1085 		wake_up(&rspi->wait);
1086 		return IRQ_HANDLED;
1087 	}
1088 
1089 	return 0;
1090 }
1091 
1092 static struct dma_chan *rspi_request_dma_chan(struct device *dev,
1093 					      enum dma_transfer_direction dir,
1094 					      unsigned int id,
1095 					      dma_addr_t port_addr)
1096 {
1097 	dma_cap_mask_t mask;
1098 	struct dma_chan *chan;
1099 	struct dma_slave_config cfg;
1100 	int ret;
1101 
1102 	dma_cap_zero(mask);
1103 	dma_cap_set(DMA_SLAVE, mask);
1104 
1105 	chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
1106 				(void *)(unsigned long)id, dev,
1107 				dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1108 	if (!chan) {
1109 		dev_warn(dev, "dma_request_slave_channel_compat failed\n");
1110 		return NULL;
1111 	}
1112 
1113 	memset(&cfg, 0, sizeof(cfg));
1114 	cfg.dst_addr = port_addr + RSPI_SPDR;
1115 	cfg.src_addr = port_addr + RSPI_SPDR;
1116 	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1117 	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1118 	cfg.direction = dir;
1119 
1120 	ret = dmaengine_slave_config(chan, &cfg);
1121 	if (ret) {
1122 		dev_warn(dev, "dmaengine_slave_config failed %d\n", ret);
1123 		dma_release_channel(chan);
1124 		return NULL;
1125 	}
1126 
1127 	return chan;
1128 }
1129 
1130 static int rspi_request_dma(struct device *dev, struct spi_controller *ctlr,
1131 			    const struct resource *res)
1132 {
1133 	unsigned int dma_tx_id, dma_rx_id;
1134 
1135 	if (dev->of_node) {
1136 		/* In the OF case we will get the slave IDs from the DT */
1137 		dma_tx_id = 0;
1138 		dma_rx_id = 0;
1139 	} else {
1140 		/* The driver assumes no error. */
1141 		return 0;
1142 	}
1143 
1144 	ctlr->dma_tx = rspi_request_dma_chan(dev, DMA_MEM_TO_DEV, dma_tx_id,
1145 					     res->start);
1146 	if (!ctlr->dma_tx)
1147 		return -ENODEV;
1148 
1149 	ctlr->dma_rx = rspi_request_dma_chan(dev, DMA_DEV_TO_MEM, dma_rx_id,
1150 					     res->start);
1151 	if (!ctlr->dma_rx) {
1152 		dma_release_channel(ctlr->dma_tx);
1153 		ctlr->dma_tx = NULL;
1154 		return -ENODEV;
1155 	}
1156 
1157 	ctlr->can_dma = rspi_can_dma;
1158 	dev_info(dev, "DMA available");
1159 	return 0;
1160 }
1161 
1162 static void rspi_release_dma(struct spi_controller *ctlr)
1163 {
1164 	if (ctlr->dma_tx)
1165 		dma_release_channel(ctlr->dma_tx);
1166 	if (ctlr->dma_rx)
1167 		dma_release_channel(ctlr->dma_rx);
1168 }
1169 
1170 static void rspi_remove(struct platform_device *pdev)
1171 {
1172 	struct rspi_data *rspi = platform_get_drvdata(pdev);
1173 
1174 	rspi_release_dma(rspi->ctlr);
1175 	pm_runtime_disable(&pdev->dev);
1176 }
1177 
1178 static const struct spi_ops rspi_ops = {
1179 	.set_config_register =	rspi_set_config_register,
1180 	.transfer_one =		rspi_transfer_one,
1181 	.min_div =		2,
1182 	.max_div =		4096,
1183 	.flags =		SPI_CONTROLLER_MUST_TX,
1184 	.fifo_size =		8,
1185 	.num_hw_ss =		2,
1186 };
1187 
1188 static const struct spi_ops rspi_rz_ops __maybe_unused = {
1189 	.set_config_register =	rspi_rz_set_config_register,
1190 	.transfer_one =		rspi_rz_transfer_one,
1191 	.min_div =		2,
1192 	.max_div =		4096,
1193 	.flags =		SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
1194 	.fifo_size =		8,	/* 8 for TX, 32 for RX */
1195 	.num_hw_ss =		1,
1196 };
1197 
1198 static const struct spi_ops qspi_ops __maybe_unused = {
1199 	.set_config_register =	qspi_set_config_register,
1200 	.transfer_one =		qspi_transfer_one,
1201 	.extra_mode_bits =	SPI_TX_DUAL | SPI_TX_QUAD |
1202 				SPI_RX_DUAL | SPI_RX_QUAD,
1203 	.min_div =		1,
1204 	.max_div =		4080,
1205 	.flags =		SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
1206 	.fifo_size =		32,
1207 	.num_hw_ss =		1,
1208 };
1209 
1210 static const struct of_device_id rspi_of_match[] __maybe_unused = {
1211 	/* RSPI on legacy SH */
1212 	{ .compatible = "renesas,rspi", .data = &rspi_ops },
1213 	/* RSPI on RZ/A1H */
1214 	{ .compatible = "renesas,rspi-rz", .data = &rspi_rz_ops },
1215 	/* QSPI on R-Car Gen2 */
1216 	{ .compatible = "renesas,qspi", .data = &qspi_ops },
1217 	{ /* sentinel */ }
1218 };
1219 
1220 MODULE_DEVICE_TABLE(of, rspi_of_match);
1221 
1222 #ifdef CONFIG_OF
1223 static void rspi_reset_control_assert(void *data)
1224 {
1225 	reset_control_assert(data);
1226 }
1227 
1228 static int rspi_parse_dt(struct device *dev, struct spi_controller *ctlr)
1229 {
1230 	struct reset_control *rstc;
1231 	u32 num_cs;
1232 	int error;
1233 
1234 	/* Parse DT properties */
1235 	error = of_property_read_u32(dev->of_node, "num-cs", &num_cs);
1236 	if (error) {
1237 		dev_err(dev, "of_property_read_u32 num-cs failed %d\n", error);
1238 		return error;
1239 	}
1240 
1241 	ctlr->num_chipselect = num_cs;
1242 
1243 	rstc = devm_reset_control_get_optional_exclusive(dev, NULL);
1244 	if (IS_ERR(rstc))
1245 		return dev_err_probe(dev, PTR_ERR(rstc),
1246 					     "failed to get reset ctrl\n");
1247 
1248 	error = reset_control_deassert(rstc);
1249 	if (error) {
1250 		dev_err(dev, "failed to deassert reset %d\n", error);
1251 		return error;
1252 	}
1253 
1254 	error = devm_add_action_or_reset(dev, rspi_reset_control_assert, rstc);
1255 	if (error) {
1256 		dev_err(dev, "failed to register assert devm action, %d\n", error);
1257 		return error;
1258 	}
1259 
1260 	return 0;
1261 }
1262 #else
1263 #define rspi_of_match	NULL
1264 static inline int rspi_parse_dt(struct device *dev, struct spi_controller *ctlr)
1265 {
1266 	return -EINVAL;
1267 }
1268 #endif /* CONFIG_OF */
1269 
1270 static int rspi_request_irq(struct device *dev, unsigned int irq,
1271 			    irq_handler_t handler, const char *suffix,
1272 			    void *dev_id)
1273 {
1274 	const char *name = devm_kasprintf(dev, GFP_KERNEL, "%s:%s",
1275 					  dev_name(dev), suffix);
1276 	if (!name)
1277 		return -ENOMEM;
1278 
1279 	return devm_request_irq(dev, irq, handler, 0, name, dev_id);
1280 }
1281 
1282 static int rspi_probe(struct platform_device *pdev)
1283 {
1284 	struct resource *res;
1285 	struct spi_controller *ctlr;
1286 	struct rspi_data *rspi;
1287 	int ret;
1288 	const struct spi_ops *ops;
1289 	unsigned long clksrc;
1290 
1291 	ctlr = spi_alloc_host(&pdev->dev, sizeof(struct rspi_data));
1292 	if (ctlr == NULL)
1293 		return -ENOMEM;
1294 
1295 	ops = of_device_get_match_data(&pdev->dev);
1296 	if (ops) {
1297 		ret = rspi_parse_dt(&pdev->dev, ctlr);
1298 		if (ret)
1299 			goto error1;
1300 	} else {
1301 		ops = (struct spi_ops *)pdev->id_entry->driver_data;
1302 		ctlr->num_chipselect = 2; /* default */
1303 	}
1304 
1305 	rspi = spi_controller_get_devdata(ctlr);
1306 	platform_set_drvdata(pdev, rspi);
1307 	rspi->ops = ops;
1308 	rspi->ctlr = ctlr;
1309 
1310 	rspi->addr = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
1311 	if (IS_ERR(rspi->addr)) {
1312 		ret = PTR_ERR(rspi->addr);
1313 		goto error1;
1314 	}
1315 
1316 	rspi->clk = devm_clk_get(&pdev->dev, NULL);
1317 	if (IS_ERR(rspi->clk)) {
1318 		dev_err(&pdev->dev, "cannot get clock\n");
1319 		ret = PTR_ERR(rspi->clk);
1320 		goto error1;
1321 	}
1322 
1323 	rspi->pdev = pdev;
1324 	pm_runtime_enable(&pdev->dev);
1325 
1326 	init_waitqueue_head(&rspi->wait);
1327 	spin_lock_init(&rspi->lock);
1328 
1329 	ctlr->bus_num = pdev->id;
1330 	ctlr->setup = rspi_setup;
1331 	ctlr->auto_runtime_pm = true;
1332 	ctlr->transfer_one = ops->transfer_one;
1333 	ctlr->prepare_message = rspi_prepare_message;
1334 	ctlr->unprepare_message = rspi_unprepare_message;
1335 	ctlr->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST |
1336 			  SPI_LOOP | ops->extra_mode_bits;
1337 	clksrc = clk_get_rate(rspi->clk);
1338 	ctlr->min_speed_hz = DIV_ROUND_UP(clksrc, ops->max_div);
1339 	ctlr->max_speed_hz = DIV_ROUND_UP(clksrc, ops->min_div);
1340 	ctlr->flags = ops->flags;
1341 	ctlr->dev.of_node = pdev->dev.of_node;
1342 	ctlr->use_gpio_descriptors = true;
1343 	ctlr->max_native_cs = rspi->ops->num_hw_ss;
1344 
1345 	ret = platform_get_irq_byname_optional(pdev, "rx");
1346 	if (ret < 0) {
1347 		ret = platform_get_irq_byname_optional(pdev, "mux");
1348 		if (ret < 0)
1349 			ret = platform_get_irq(pdev, 0);
1350 		if (ret >= 0)
1351 			rspi->rx_irq = rspi->tx_irq = ret;
1352 	} else {
1353 		rspi->rx_irq = ret;
1354 		ret = platform_get_irq_byname(pdev, "tx");
1355 		if (ret >= 0)
1356 			rspi->tx_irq = ret;
1357 	}
1358 
1359 	if (rspi->rx_irq == rspi->tx_irq) {
1360 		/* Single multiplexed interrupt */
1361 		ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_mux,
1362 				       "mux", rspi);
1363 	} else {
1364 		/* Multi-interrupt mode, only SPRI and SPTI are used */
1365 		ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_rx,
1366 				       "rx", rspi);
1367 		if (!ret)
1368 			ret = rspi_request_irq(&pdev->dev, rspi->tx_irq,
1369 					       rspi_irq_tx, "tx", rspi);
1370 	}
1371 	if (ret < 0) {
1372 		dev_err(&pdev->dev, "request_irq error\n");
1373 		goto error2;
1374 	}
1375 
1376 	ret = rspi_request_dma(&pdev->dev, ctlr, res);
1377 	if (ret < 0)
1378 		dev_warn(&pdev->dev, "DMA not available, using PIO\n");
1379 
1380 	ret = devm_spi_register_controller(&pdev->dev, ctlr);
1381 	if (ret < 0) {
1382 		dev_err(&pdev->dev, "devm_spi_register_controller error.\n");
1383 		goto error3;
1384 	}
1385 
1386 	dev_info(&pdev->dev, "probed\n");
1387 
1388 	return 0;
1389 
1390 error3:
1391 	rspi_release_dma(ctlr);
1392 error2:
1393 	pm_runtime_disable(&pdev->dev);
1394 error1:
1395 	spi_controller_put(ctlr);
1396 
1397 	return ret;
1398 }
1399 
1400 static const struct platform_device_id spi_driver_ids[] = {
1401 	{ "rspi",	(kernel_ulong_t)&rspi_ops },
1402 	{},
1403 };
1404 
1405 MODULE_DEVICE_TABLE(platform, spi_driver_ids);
1406 
1407 #ifdef CONFIG_PM_SLEEP
1408 static int rspi_suspend(struct device *dev)
1409 {
1410 	struct rspi_data *rspi = dev_get_drvdata(dev);
1411 
1412 	return spi_controller_suspend(rspi->ctlr);
1413 }
1414 
1415 static int rspi_resume(struct device *dev)
1416 {
1417 	struct rspi_data *rspi = dev_get_drvdata(dev);
1418 
1419 	return spi_controller_resume(rspi->ctlr);
1420 }
1421 
1422 static SIMPLE_DEV_PM_OPS(rspi_pm_ops, rspi_suspend, rspi_resume);
1423 #define DEV_PM_OPS	&rspi_pm_ops
1424 #else
1425 #define DEV_PM_OPS	NULL
1426 #endif /* CONFIG_PM_SLEEP */
1427 
1428 static struct platform_driver rspi_driver = {
1429 	.probe =	rspi_probe,
1430 	.remove =	rspi_remove,
1431 	.id_table =	spi_driver_ids,
1432 	.driver		= {
1433 		.name = "renesas_spi",
1434 		.pm = DEV_PM_OPS,
1435 		.of_match_table = of_match_ptr(rspi_of_match),
1436 	},
1437 };
1438 module_platform_driver(rspi_driver);
1439 
1440 MODULE_DESCRIPTION("Renesas RSPI bus driver");
1441 MODULE_LICENSE("GPL v2");
1442 MODULE_AUTHOR("Yoshihiro Shimoda");
1443