xref: /openbmc/linux/drivers/spi/spi-rspi.c (revision 2bc7d3e0)
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 	} else {
617 		if (!ret) {
618 			dev_err(&rspi->ctlr->dev, "DMA timeout\n");
619 			ret = -ETIMEDOUT;
620 		}
621 		if (tx)
622 			dmaengine_terminate_sync(rspi->ctlr->dma_tx);
623 		if (rx)
624 			dmaengine_terminate_sync(rspi->ctlr->dma_rx);
625 	}
626 
627 	rspi_disable_irq(rspi, irq_mask);
628 
629 	if (tx)
630 		enable_irq(rspi->tx_irq);
631 	if (rx && rspi->rx_irq != other_irq)
632 		enable_irq(rspi->rx_irq);
633 
634 	return ret;
635 
636 no_dma_tx:
637 	if (rx)
638 		dmaengine_terminate_sync(rspi->ctlr->dma_rx);
639 no_dma_rx:
640 	if (ret == -EAGAIN) {
641 		dev_warn_once(&rspi->ctlr->dev,
642 			      "DMA not available, falling back to PIO\n");
643 	}
644 	return ret;
645 }
646 
647 static void rspi_receive_init(const struct rspi_data *rspi)
648 {
649 	u8 spsr;
650 
651 	spsr = rspi_read8(rspi, RSPI_SPSR);
652 	if (spsr & SPSR_SPRF)
653 		rspi_read_data(rspi);	/* dummy read */
654 	if (spsr & SPSR_OVRF)
655 		rspi_write8(rspi, rspi_read8(rspi, RSPI_SPSR) & ~SPSR_OVRF,
656 			    RSPI_SPSR);
657 }
658 
659 static void rspi_rz_receive_init(const struct rspi_data *rspi)
660 {
661 	rspi_receive_init(rspi);
662 	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, RSPI_SPBFCR);
663 	rspi_write8(rspi, 0, RSPI_SPBFCR);
664 }
665 
666 static void qspi_receive_init(const struct rspi_data *rspi)
667 {
668 	u8 spsr;
669 
670 	spsr = rspi_read8(rspi, RSPI_SPSR);
671 	if (spsr & SPSR_SPRF)
672 		rspi_read_data(rspi);   /* dummy read */
673 	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
674 	rspi_write8(rspi, 0, QSPI_SPBFCR);
675 }
676 
677 static bool __rspi_can_dma(const struct rspi_data *rspi,
678 			   const struct spi_transfer *xfer)
679 {
680 	return xfer->len > rspi->ops->fifo_size;
681 }
682 
683 static bool rspi_can_dma(struct spi_controller *ctlr, struct spi_device *spi,
684 			 struct spi_transfer *xfer)
685 {
686 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
687 
688 	return __rspi_can_dma(rspi, xfer);
689 }
690 
691 static int rspi_dma_check_then_transfer(struct rspi_data *rspi,
692 					 struct spi_transfer *xfer)
693 {
694 	if (!rspi->ctlr->can_dma || !__rspi_can_dma(rspi, xfer))
695 		return -EAGAIN;
696 
697 	/* rx_buf can be NULL on RSPI on SH in TX-only Mode */
698 	return rspi_dma_transfer(rspi, &xfer->tx_sg,
699 				xfer->rx_buf ? &xfer->rx_sg : NULL);
700 }
701 
702 static int rspi_common_transfer(struct rspi_data *rspi,
703 				struct spi_transfer *xfer)
704 {
705 	int ret;
706 
707 	xfer->effective_speed_hz = rspi->speed_hz;
708 
709 	ret = rspi_dma_check_then_transfer(rspi, xfer);
710 	if (ret != -EAGAIN)
711 		return ret;
712 
713 	ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len);
714 	if (ret < 0)
715 		return ret;
716 
717 	/* Wait for the last transmission */
718 	rspi_wait_for_tx_empty(rspi);
719 
720 	return 0;
721 }
722 
723 static int rspi_transfer_one(struct spi_controller *ctlr,
724 			     struct spi_device *spi, struct spi_transfer *xfer)
725 {
726 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
727 	u8 spcr;
728 
729 	spcr = rspi_read8(rspi, RSPI_SPCR);
730 	if (xfer->rx_buf) {
731 		rspi_receive_init(rspi);
732 		spcr &= ~SPCR_TXMD;
733 	} else {
734 		spcr |= SPCR_TXMD;
735 	}
736 	rspi_write8(rspi, spcr, RSPI_SPCR);
737 
738 	return rspi_common_transfer(rspi, xfer);
739 }
740 
741 static int rspi_rz_transfer_one(struct spi_controller *ctlr,
742 				struct spi_device *spi,
743 				struct spi_transfer *xfer)
744 {
745 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
746 
747 	rspi_rz_receive_init(rspi);
748 
749 	return rspi_common_transfer(rspi, xfer);
750 }
751 
752 static int qspi_trigger_transfer_out_in(struct rspi_data *rspi, const u8 *tx,
753 					u8 *rx, unsigned int len)
754 {
755 	unsigned int i, n;
756 	int ret;
757 
758 	while (len > 0) {
759 		n = qspi_set_send_trigger(rspi, len);
760 		qspi_set_receive_trigger(rspi, len);
761 		ret = rspi_wait_for_tx_empty(rspi);
762 		if (ret < 0) {
763 			dev_err(&rspi->ctlr->dev, "transmit timeout\n");
764 			return ret;
765 		}
766 		for (i = 0; i < n; i++)
767 			rspi_write_data(rspi, *tx++);
768 
769 		ret = rspi_wait_for_rx_full(rspi);
770 		if (ret < 0) {
771 			dev_err(&rspi->ctlr->dev, "receive timeout\n");
772 			return ret;
773 		}
774 		for (i = 0; i < n; i++)
775 			*rx++ = rspi_read_data(rspi);
776 
777 		len -= n;
778 	}
779 
780 	return 0;
781 }
782 
783 static int qspi_transfer_out_in(struct rspi_data *rspi,
784 				struct spi_transfer *xfer)
785 {
786 	int ret;
787 
788 	qspi_receive_init(rspi);
789 
790 	ret = rspi_dma_check_then_transfer(rspi, xfer);
791 	if (ret != -EAGAIN)
792 		return ret;
793 
794 	return qspi_trigger_transfer_out_in(rspi, xfer->tx_buf,
795 					    xfer->rx_buf, xfer->len);
796 }
797 
798 static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer)
799 {
800 	const u8 *tx = xfer->tx_buf;
801 	unsigned int n = xfer->len;
802 	unsigned int i, len;
803 	int ret;
804 
805 	if (rspi->ctlr->can_dma && __rspi_can_dma(rspi, xfer)) {
806 		ret = rspi_dma_transfer(rspi, &xfer->tx_sg, NULL);
807 		if (ret != -EAGAIN)
808 			return ret;
809 	}
810 
811 	while (n > 0) {
812 		len = qspi_set_send_trigger(rspi, n);
813 		ret = rspi_wait_for_tx_empty(rspi);
814 		if (ret < 0) {
815 			dev_err(&rspi->ctlr->dev, "transmit timeout\n");
816 			return ret;
817 		}
818 		for (i = 0; i < len; i++)
819 			rspi_write_data(rspi, *tx++);
820 
821 		n -= len;
822 	}
823 
824 	/* Wait for the last transmission */
825 	rspi_wait_for_tx_empty(rspi);
826 
827 	return 0;
828 }
829 
830 static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer)
831 {
832 	u8 *rx = xfer->rx_buf;
833 	unsigned int n = xfer->len;
834 	unsigned int i, len;
835 	int ret;
836 
837 	if (rspi->ctlr->can_dma && __rspi_can_dma(rspi, xfer)) {
838 		ret = rspi_dma_transfer(rspi, NULL, &xfer->rx_sg);
839 		if (ret != -EAGAIN)
840 			return ret;
841 	}
842 
843 	while (n > 0) {
844 		len = qspi_set_receive_trigger(rspi, n);
845 		ret = rspi_wait_for_rx_full(rspi);
846 		if (ret < 0) {
847 			dev_err(&rspi->ctlr->dev, "receive timeout\n");
848 			return ret;
849 		}
850 		for (i = 0; i < len; i++)
851 			*rx++ = rspi_read_data(rspi);
852 
853 		n -= len;
854 	}
855 
856 	return 0;
857 }
858 
859 static int qspi_transfer_one(struct spi_controller *ctlr,
860 			     struct spi_device *spi, struct spi_transfer *xfer)
861 {
862 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
863 
864 	xfer->effective_speed_hz = rspi->speed_hz;
865 	if (spi->mode & SPI_LOOP) {
866 		return qspi_transfer_out_in(rspi, xfer);
867 	} else if (xfer->tx_nbits > SPI_NBITS_SINGLE) {
868 		/* Quad or Dual SPI Write */
869 		return qspi_transfer_out(rspi, xfer);
870 	} else if (xfer->rx_nbits > SPI_NBITS_SINGLE) {
871 		/* Quad or Dual SPI Read */
872 		return qspi_transfer_in(rspi, xfer);
873 	} else {
874 		/* Single SPI Transfer */
875 		return qspi_transfer_out_in(rspi, xfer);
876 	}
877 }
878 
879 static u16 qspi_transfer_mode(const struct spi_transfer *xfer)
880 {
881 	if (xfer->tx_buf)
882 		switch (xfer->tx_nbits) {
883 		case SPI_NBITS_QUAD:
884 			return SPCMD_SPIMOD_QUAD;
885 		case SPI_NBITS_DUAL:
886 			return SPCMD_SPIMOD_DUAL;
887 		default:
888 			return 0;
889 		}
890 	if (xfer->rx_buf)
891 		switch (xfer->rx_nbits) {
892 		case SPI_NBITS_QUAD:
893 			return SPCMD_SPIMOD_QUAD | SPCMD_SPRW;
894 		case SPI_NBITS_DUAL:
895 			return SPCMD_SPIMOD_DUAL | SPCMD_SPRW;
896 		default:
897 			return 0;
898 		}
899 
900 	return 0;
901 }
902 
903 static int qspi_setup_sequencer(struct rspi_data *rspi,
904 				const struct spi_message *msg)
905 {
906 	const struct spi_transfer *xfer;
907 	unsigned int i = 0, len = 0;
908 	u16 current_mode = 0xffff, mode;
909 
910 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
911 		mode = qspi_transfer_mode(xfer);
912 		if (mode == current_mode) {
913 			len += xfer->len;
914 			continue;
915 		}
916 
917 		/* Transfer mode change */
918 		if (i) {
919 			/* Set transfer data length of previous transfer */
920 			rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
921 		}
922 
923 		if (i >= QSPI_NUM_SPCMD) {
924 			dev_err(&msg->spi->dev,
925 				"Too many different transfer modes");
926 			return -EINVAL;
927 		}
928 
929 		/* Program transfer mode for this transfer */
930 		rspi_write16(rspi, rspi->spcmd | mode, RSPI_SPCMD(i));
931 		current_mode = mode;
932 		len = xfer->len;
933 		i++;
934 	}
935 	if (i) {
936 		/* Set final transfer data length and sequence length */
937 		rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
938 		rspi_write8(rspi, i - 1, RSPI_SPSCR);
939 	}
940 
941 	return 0;
942 }
943 
944 static int rspi_setup(struct spi_device *spi)
945 {
946 	struct rspi_data *rspi = spi_controller_get_devdata(spi->controller);
947 	u8 sslp;
948 
949 	if (spi->cs_gpiod)
950 		return 0;
951 
952 	pm_runtime_get_sync(&rspi->pdev->dev);
953 	spin_lock_irq(&rspi->lock);
954 
955 	sslp = rspi_read8(rspi, RSPI_SSLP);
956 	if (spi->mode & SPI_CS_HIGH)
957 		sslp |= SSLP_SSLP(spi->chip_select);
958 	else
959 		sslp &= ~SSLP_SSLP(spi->chip_select);
960 	rspi_write8(rspi, sslp, RSPI_SSLP);
961 
962 	spin_unlock_irq(&rspi->lock);
963 	pm_runtime_put(&rspi->pdev->dev);
964 	return 0;
965 }
966 
967 static int rspi_prepare_message(struct spi_controller *ctlr,
968 				struct spi_message *msg)
969 {
970 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
971 	struct spi_device *spi = msg->spi;
972 	const struct spi_transfer *xfer;
973 	int ret;
974 
975 	/*
976 	 * As the Bit Rate Register must not be changed while the device is
977 	 * active, all transfers in a message must use the same bit rate.
978 	 * In theory, the sequencer could be enabled, and each Command Register
979 	 * could divide the base bit rate by a different value.
980 	 * However, most RSPI variants do not have Transfer Data Length
981 	 * Multiplier Setting Registers, so each sequence step would be limited
982 	 * to a single word, making this feature unsuitable for large
983 	 * transfers, which would gain most from it.
984 	 */
985 	rspi->speed_hz = spi->max_speed_hz;
986 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
987 		if (xfer->speed_hz < rspi->speed_hz)
988 			rspi->speed_hz = xfer->speed_hz;
989 	}
990 
991 	rspi->spcmd = SPCMD_SSLKP;
992 	if (spi->mode & SPI_CPOL)
993 		rspi->spcmd |= SPCMD_CPOL;
994 	if (spi->mode & SPI_CPHA)
995 		rspi->spcmd |= SPCMD_CPHA;
996 	if (spi->mode & SPI_LSB_FIRST)
997 		rspi->spcmd |= SPCMD_LSBF;
998 
999 	/* Configure slave signal to assert */
1000 	rspi->spcmd |= SPCMD_SSLA(spi->cs_gpiod ? rspi->ctlr->unused_native_cs
1001 						: spi->chip_select);
1002 
1003 	/* CMOS output mode and MOSI signal from previous transfer */
1004 	rspi->sppcr = 0;
1005 	if (spi->mode & SPI_LOOP)
1006 		rspi->sppcr |= SPPCR_SPLP;
1007 
1008 	rspi->ops->set_config_register(rspi, 8);
1009 
1010 	if (msg->spi->mode &
1011 	    (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)) {
1012 		/* Setup sequencer for messages with multiple transfer modes */
1013 		ret = qspi_setup_sequencer(rspi, msg);
1014 		if (ret < 0)
1015 			return ret;
1016 	}
1017 
1018 	/* Enable SPI function in master mode */
1019 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_SPE, RSPI_SPCR);
1020 	return 0;
1021 }
1022 
1023 static int rspi_unprepare_message(struct spi_controller *ctlr,
1024 				  struct spi_message *msg)
1025 {
1026 	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
1027 
1028 	/* Disable SPI function */
1029 	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_SPE, RSPI_SPCR);
1030 
1031 	/* Reset sequencer for Single SPI Transfers */
1032 	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
1033 	rspi_write8(rspi, 0, RSPI_SPSCR);
1034 	return 0;
1035 }
1036 
1037 static irqreturn_t rspi_irq_mux(int irq, void *_sr)
1038 {
1039 	struct rspi_data *rspi = _sr;
1040 	u8 spsr;
1041 	irqreturn_t ret = IRQ_NONE;
1042 	u8 disable_irq = 0;
1043 
1044 	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
1045 	if (spsr & SPSR_SPRF)
1046 		disable_irq |= SPCR_SPRIE;
1047 	if (spsr & SPSR_SPTEF)
1048 		disable_irq |= SPCR_SPTIE;
1049 
1050 	if (disable_irq) {
1051 		ret = IRQ_HANDLED;
1052 		rspi_disable_irq(rspi, disable_irq);
1053 		wake_up(&rspi->wait);
1054 	}
1055 
1056 	return ret;
1057 }
1058 
1059 static irqreturn_t rspi_irq_rx(int irq, void *_sr)
1060 {
1061 	struct rspi_data *rspi = _sr;
1062 	u8 spsr;
1063 
1064 	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
1065 	if (spsr & SPSR_SPRF) {
1066 		rspi_disable_irq(rspi, SPCR_SPRIE);
1067 		wake_up(&rspi->wait);
1068 		return IRQ_HANDLED;
1069 	}
1070 
1071 	return 0;
1072 }
1073 
1074 static irqreturn_t rspi_irq_tx(int irq, void *_sr)
1075 {
1076 	struct rspi_data *rspi = _sr;
1077 	u8 spsr;
1078 
1079 	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
1080 	if (spsr & SPSR_SPTEF) {
1081 		rspi_disable_irq(rspi, SPCR_SPTIE);
1082 		wake_up(&rspi->wait);
1083 		return IRQ_HANDLED;
1084 	}
1085 
1086 	return 0;
1087 }
1088 
1089 static struct dma_chan *rspi_request_dma_chan(struct device *dev,
1090 					      enum dma_transfer_direction dir,
1091 					      unsigned int id,
1092 					      dma_addr_t port_addr)
1093 {
1094 	dma_cap_mask_t mask;
1095 	struct dma_chan *chan;
1096 	struct dma_slave_config cfg;
1097 	int ret;
1098 
1099 	dma_cap_zero(mask);
1100 	dma_cap_set(DMA_SLAVE, mask);
1101 
1102 	chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
1103 				(void *)(unsigned long)id, dev,
1104 				dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1105 	if (!chan) {
1106 		dev_warn(dev, "dma_request_slave_channel_compat failed\n");
1107 		return NULL;
1108 	}
1109 
1110 	memset(&cfg, 0, sizeof(cfg));
1111 	cfg.dst_addr = port_addr + RSPI_SPDR;
1112 	cfg.src_addr = port_addr + RSPI_SPDR;
1113 	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1114 	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1115 	cfg.direction = dir;
1116 
1117 	ret = dmaengine_slave_config(chan, &cfg);
1118 	if (ret) {
1119 		dev_warn(dev, "dmaengine_slave_config failed %d\n", ret);
1120 		dma_release_channel(chan);
1121 		return NULL;
1122 	}
1123 
1124 	return chan;
1125 }
1126 
1127 static int rspi_request_dma(struct device *dev, struct spi_controller *ctlr,
1128 			    const struct resource *res)
1129 {
1130 	const struct rspi_plat_data *rspi_pd = dev_get_platdata(dev);
1131 	unsigned int dma_tx_id, dma_rx_id;
1132 
1133 	if (dev->of_node) {
1134 		/* In the OF case we will get the slave IDs from the DT */
1135 		dma_tx_id = 0;
1136 		dma_rx_id = 0;
1137 	} else if (rspi_pd && rspi_pd->dma_tx_id && rspi_pd->dma_rx_id) {
1138 		dma_tx_id = rspi_pd->dma_tx_id;
1139 		dma_rx_id = rspi_pd->dma_rx_id;
1140 	} else {
1141 		/* The driver assumes no error. */
1142 		return 0;
1143 	}
1144 
1145 	ctlr->dma_tx = rspi_request_dma_chan(dev, DMA_MEM_TO_DEV, dma_tx_id,
1146 					     res->start);
1147 	if (!ctlr->dma_tx)
1148 		return -ENODEV;
1149 
1150 	ctlr->dma_rx = rspi_request_dma_chan(dev, DMA_DEV_TO_MEM, dma_rx_id,
1151 					     res->start);
1152 	if (!ctlr->dma_rx) {
1153 		dma_release_channel(ctlr->dma_tx);
1154 		ctlr->dma_tx = NULL;
1155 		return -ENODEV;
1156 	}
1157 
1158 	ctlr->can_dma = rspi_can_dma;
1159 	dev_info(dev, "DMA available");
1160 	return 0;
1161 }
1162 
1163 static void rspi_release_dma(struct spi_controller *ctlr)
1164 {
1165 	if (ctlr->dma_tx)
1166 		dma_release_channel(ctlr->dma_tx);
1167 	if (ctlr->dma_rx)
1168 		dma_release_channel(ctlr->dma_rx);
1169 }
1170 
1171 static int rspi_remove(struct platform_device *pdev)
1172 {
1173 	struct rspi_data *rspi = platform_get_drvdata(pdev);
1174 
1175 	rspi_release_dma(rspi->ctlr);
1176 	pm_runtime_disable(&pdev->dev);
1177 
1178 	return 0;
1179 }
1180 
1181 static const struct spi_ops rspi_ops = {
1182 	.set_config_register =	rspi_set_config_register,
1183 	.transfer_one =		rspi_transfer_one,
1184 	.min_div =		2,
1185 	.max_div =		4096,
1186 	.flags =		SPI_CONTROLLER_MUST_TX,
1187 	.fifo_size =		8,
1188 	.num_hw_ss =		2,
1189 };
1190 
1191 static const struct spi_ops rspi_rz_ops = {
1192 	.set_config_register =	rspi_rz_set_config_register,
1193 	.transfer_one =		rspi_rz_transfer_one,
1194 	.min_div =		2,
1195 	.max_div =		4096,
1196 	.flags =		SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
1197 	.fifo_size =		8,	/* 8 for TX, 32 for RX */
1198 	.num_hw_ss =		1,
1199 };
1200 
1201 static const struct spi_ops qspi_ops = {
1202 	.set_config_register =	qspi_set_config_register,
1203 	.transfer_one =		qspi_transfer_one,
1204 	.extra_mode_bits =	SPI_TX_DUAL | SPI_TX_QUAD |
1205 				SPI_RX_DUAL | SPI_RX_QUAD,
1206 	.min_div =		1,
1207 	.max_div =		4080,
1208 	.flags =		SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
1209 	.fifo_size =		32,
1210 	.num_hw_ss =		1,
1211 };
1212 
1213 #ifdef CONFIG_OF
1214 static const struct of_device_id rspi_of_match[] = {
1215 	/* RSPI on legacy SH */
1216 	{ .compatible = "renesas,rspi", .data = &rspi_ops },
1217 	/* RSPI on RZ/A1H */
1218 	{ .compatible = "renesas,rspi-rz", .data = &rspi_rz_ops },
1219 	/* QSPI on R-Car Gen2 */
1220 	{ .compatible = "renesas,qspi", .data = &qspi_ops },
1221 	{ /* sentinel */ }
1222 };
1223 
1224 MODULE_DEVICE_TABLE(of, rspi_of_match);
1225 
1226 static void rspi_reset_control_assert(void *data)
1227 {
1228 	reset_control_assert(data);
1229 }
1230 
1231 static int rspi_parse_dt(struct device *dev, struct spi_controller *ctlr)
1232 {
1233 	struct reset_control *rstc;
1234 	u32 num_cs;
1235 	int error;
1236 
1237 	/* Parse DT properties */
1238 	error = of_property_read_u32(dev->of_node, "num-cs", &num_cs);
1239 	if (error) {
1240 		dev_err(dev, "of_property_read_u32 num-cs failed %d\n", error);
1241 		return error;
1242 	}
1243 
1244 	ctlr->num_chipselect = num_cs;
1245 
1246 	rstc = devm_reset_control_get_optional_exclusive(dev, NULL);
1247 	if (IS_ERR(rstc))
1248 		return dev_err_probe(dev, PTR_ERR(rstc),
1249 					     "failed to get reset ctrl\n");
1250 
1251 	error = reset_control_deassert(rstc);
1252 	if (error) {
1253 		dev_err(dev, "failed to deassert reset %d\n", error);
1254 		return error;
1255 	}
1256 
1257 	error = devm_add_action_or_reset(dev, rspi_reset_control_assert, rstc);
1258 	if (error) {
1259 		dev_err(dev, "failed to register assert devm action, %d\n", error);
1260 		return error;
1261 	}
1262 
1263 	return 0;
1264 }
1265 #else
1266 #define rspi_of_match	NULL
1267 static inline int rspi_parse_dt(struct device *dev, struct spi_controller *ctlr)
1268 {
1269 	return -EINVAL;
1270 }
1271 #endif /* CONFIG_OF */
1272 
1273 static int rspi_request_irq(struct device *dev, unsigned int irq,
1274 			    irq_handler_t handler, const char *suffix,
1275 			    void *dev_id)
1276 {
1277 	const char *name = devm_kasprintf(dev, GFP_KERNEL, "%s:%s",
1278 					  dev_name(dev), suffix);
1279 	if (!name)
1280 		return -ENOMEM;
1281 
1282 	return devm_request_irq(dev, irq, handler, 0, name, dev_id);
1283 }
1284 
1285 static int rspi_probe(struct platform_device *pdev)
1286 {
1287 	struct resource *res;
1288 	struct spi_controller *ctlr;
1289 	struct rspi_data *rspi;
1290 	int ret;
1291 	const struct rspi_plat_data *rspi_pd;
1292 	const struct spi_ops *ops;
1293 	unsigned long clksrc;
1294 
1295 	ctlr = spi_alloc_master(&pdev->dev, sizeof(struct rspi_data));
1296 	if (ctlr == NULL)
1297 		return -ENOMEM;
1298 
1299 	ops = of_device_get_match_data(&pdev->dev);
1300 	if (ops) {
1301 		ret = rspi_parse_dt(&pdev->dev, ctlr);
1302 		if (ret)
1303 			goto error1;
1304 	} else {
1305 		ops = (struct spi_ops *)pdev->id_entry->driver_data;
1306 		rspi_pd = dev_get_platdata(&pdev->dev);
1307 		if (rspi_pd && rspi_pd->num_chipselect)
1308 			ctlr->num_chipselect = rspi_pd->num_chipselect;
1309 		else
1310 			ctlr->num_chipselect = 2; /* default */
1311 	}
1312 
1313 	rspi = spi_controller_get_devdata(ctlr);
1314 	platform_set_drvdata(pdev, rspi);
1315 	rspi->ops = ops;
1316 	rspi->ctlr = ctlr;
1317 
1318 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1319 	rspi->addr = devm_ioremap_resource(&pdev->dev, res);
1320 	if (IS_ERR(rspi->addr)) {
1321 		ret = PTR_ERR(rspi->addr);
1322 		goto error1;
1323 	}
1324 
1325 	rspi->clk = devm_clk_get(&pdev->dev, NULL);
1326 	if (IS_ERR(rspi->clk)) {
1327 		dev_err(&pdev->dev, "cannot get clock\n");
1328 		ret = PTR_ERR(rspi->clk);
1329 		goto error1;
1330 	}
1331 
1332 	rspi->pdev = pdev;
1333 	pm_runtime_enable(&pdev->dev);
1334 
1335 	init_waitqueue_head(&rspi->wait);
1336 	spin_lock_init(&rspi->lock);
1337 
1338 	ctlr->bus_num = pdev->id;
1339 	ctlr->setup = rspi_setup;
1340 	ctlr->auto_runtime_pm = true;
1341 	ctlr->transfer_one = ops->transfer_one;
1342 	ctlr->prepare_message = rspi_prepare_message;
1343 	ctlr->unprepare_message = rspi_unprepare_message;
1344 	ctlr->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST |
1345 			  SPI_LOOP | ops->extra_mode_bits;
1346 	clksrc = clk_get_rate(rspi->clk);
1347 	ctlr->min_speed_hz = DIV_ROUND_UP(clksrc, ops->max_div);
1348 	ctlr->max_speed_hz = DIV_ROUND_UP(clksrc, ops->min_div);
1349 	ctlr->flags = ops->flags;
1350 	ctlr->dev.of_node = pdev->dev.of_node;
1351 	ctlr->use_gpio_descriptors = true;
1352 	ctlr->max_native_cs = rspi->ops->num_hw_ss;
1353 
1354 	ret = platform_get_irq_byname_optional(pdev, "rx");
1355 	if (ret < 0) {
1356 		ret = platform_get_irq_byname_optional(pdev, "mux");
1357 		if (ret < 0)
1358 			ret = platform_get_irq(pdev, 0);
1359 		if (ret >= 0)
1360 			rspi->rx_irq = rspi->tx_irq = ret;
1361 	} else {
1362 		rspi->rx_irq = ret;
1363 		ret = platform_get_irq_byname(pdev, "tx");
1364 		if (ret >= 0)
1365 			rspi->tx_irq = ret;
1366 	}
1367 
1368 	if (rspi->rx_irq == rspi->tx_irq) {
1369 		/* Single multiplexed interrupt */
1370 		ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_mux,
1371 				       "mux", rspi);
1372 	} else {
1373 		/* Multi-interrupt mode, only SPRI and SPTI are used */
1374 		ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_rx,
1375 				       "rx", rspi);
1376 		if (!ret)
1377 			ret = rspi_request_irq(&pdev->dev, rspi->tx_irq,
1378 					       rspi_irq_tx, "tx", rspi);
1379 	}
1380 	if (ret < 0) {
1381 		dev_err(&pdev->dev, "request_irq error\n");
1382 		goto error2;
1383 	}
1384 
1385 	ret = rspi_request_dma(&pdev->dev, ctlr, res);
1386 	if (ret < 0)
1387 		dev_warn(&pdev->dev, "DMA not available, using PIO\n");
1388 
1389 	ret = devm_spi_register_controller(&pdev->dev, ctlr);
1390 	if (ret < 0) {
1391 		dev_err(&pdev->dev, "devm_spi_register_controller error.\n");
1392 		goto error3;
1393 	}
1394 
1395 	dev_info(&pdev->dev, "probed\n");
1396 
1397 	return 0;
1398 
1399 error3:
1400 	rspi_release_dma(ctlr);
1401 error2:
1402 	pm_runtime_disable(&pdev->dev);
1403 error1:
1404 	spi_controller_put(ctlr);
1405 
1406 	return ret;
1407 }
1408 
1409 static const struct platform_device_id spi_driver_ids[] = {
1410 	{ "rspi",	(kernel_ulong_t)&rspi_ops },
1411 	{},
1412 };
1413 
1414 MODULE_DEVICE_TABLE(platform, spi_driver_ids);
1415 
1416 #ifdef CONFIG_PM_SLEEP
1417 static int rspi_suspend(struct device *dev)
1418 {
1419 	struct rspi_data *rspi = dev_get_drvdata(dev);
1420 
1421 	return spi_controller_suspend(rspi->ctlr);
1422 }
1423 
1424 static int rspi_resume(struct device *dev)
1425 {
1426 	struct rspi_data *rspi = dev_get_drvdata(dev);
1427 
1428 	return spi_controller_resume(rspi->ctlr);
1429 }
1430 
1431 static SIMPLE_DEV_PM_OPS(rspi_pm_ops, rspi_suspend, rspi_resume);
1432 #define DEV_PM_OPS	&rspi_pm_ops
1433 #else
1434 #define DEV_PM_OPS	NULL
1435 #endif /* CONFIG_PM_SLEEP */
1436 
1437 static struct platform_driver rspi_driver = {
1438 	.probe =	rspi_probe,
1439 	.remove =	rspi_remove,
1440 	.id_table =	spi_driver_ids,
1441 	.driver		= {
1442 		.name = "renesas_spi",
1443 		.pm = DEV_PM_OPS,
1444 		.of_match_table = of_match_ptr(rspi_of_match),
1445 	},
1446 };
1447 module_platform_driver(rspi_driver);
1448 
1449 MODULE_DESCRIPTION("Renesas RSPI bus driver");
1450 MODULE_LICENSE("GPL v2");
1451 MODULE_AUTHOR("Yoshihiro Shimoda");
1452