1 // SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
2 /*
3  * Copyright (C) 2019, STMicroelectronics - All Rights Reserved
4  *
5  * Driver for STMicroelectronics Serial peripheral interface (SPI)
6  */
7 
8 #define LOG_CATEGORY UCLASS_SPI
9 
10 #include <common.h>
11 #include <clk.h>
12 #include <dm.h>
13 #include <errno.h>
14 #include <log.h>
15 #include <malloc.h>
16 #include <reset.h>
17 #include <spi.h>
18 #include <dm/device_compat.h>
19 #include <linux/bitops.h>
20 #include <linux/delay.h>
21 
22 #include <asm/io.h>
23 #include <asm/gpio.h>
24 #include <linux/bitfield.h>
25 #include <linux/iopoll.h>
26 
27 /* STM32 SPI registers */
28 #define STM32_SPI_CR1		0x00
29 #define STM32_SPI_CR2		0x04
30 #define STM32_SPI_CFG1		0x08
31 #define STM32_SPI_CFG2		0x0C
32 #define STM32_SPI_SR		0x14
33 #define STM32_SPI_IFCR		0x18
34 #define STM32_SPI_TXDR		0x20
35 #define STM32_SPI_RXDR		0x30
36 #define STM32_SPI_I2SCFGR	0x50
37 
38 /* STM32_SPI_CR1 bit fields */
39 #define SPI_CR1_SPE		BIT(0)
40 #define SPI_CR1_MASRX		BIT(8)
41 #define SPI_CR1_CSTART		BIT(9)
42 #define SPI_CR1_CSUSP		BIT(10)
43 #define SPI_CR1_HDDIR		BIT(11)
44 #define SPI_CR1_SSI		BIT(12)
45 
46 /* STM32_SPI_CR2 bit fields */
47 #define SPI_CR2_TSIZE		GENMASK(15, 0)
48 
49 /* STM32_SPI_CFG1 bit fields */
50 #define SPI_CFG1_DSIZE		GENMASK(4, 0)
51 #define SPI_CFG1_DSIZE_MIN	3
52 #define SPI_CFG1_FTHLV_SHIFT	5
53 #define SPI_CFG1_FTHLV		GENMASK(8, 5)
54 #define SPI_CFG1_MBR_SHIFT	28
55 #define SPI_CFG1_MBR		GENMASK(30, 28)
56 #define SPI_CFG1_MBR_MIN	0
57 #define SPI_CFG1_MBR_MAX	FIELD_GET(SPI_CFG1_MBR, SPI_CFG1_MBR)
58 
59 /* STM32_SPI_CFG2 bit fields */
60 #define SPI_CFG2_COMM_SHIFT	17
61 #define SPI_CFG2_COMM		GENMASK(18, 17)
62 #define SPI_CFG2_MASTER		BIT(22)
63 #define SPI_CFG2_LSBFRST	BIT(23)
64 #define SPI_CFG2_CPHA		BIT(24)
65 #define SPI_CFG2_CPOL		BIT(25)
66 #define SPI_CFG2_SSM		BIT(26)
67 #define SPI_CFG2_AFCNTR		BIT(31)
68 
69 /* STM32_SPI_SR bit fields */
70 #define SPI_SR_RXP		BIT(0)
71 #define SPI_SR_TXP		BIT(1)
72 #define SPI_SR_EOT		BIT(3)
73 #define SPI_SR_TXTF		BIT(4)
74 #define SPI_SR_OVR		BIT(6)
75 #define SPI_SR_SUSP		BIT(11)
76 #define SPI_SR_RXPLVL_SHIFT	13
77 #define SPI_SR_RXPLVL		GENMASK(14, 13)
78 #define SPI_SR_RXWNE		BIT(15)
79 
80 /* STM32_SPI_IFCR bit fields */
81 #define SPI_IFCR_ALL		GENMASK(11, 3)
82 
83 /* STM32_SPI_I2SCFGR bit fields */
84 #define SPI_I2SCFGR_I2SMOD	BIT(0)
85 
86 #define MAX_CS_COUNT	4
87 
88 /* SPI Master Baud Rate min/max divisor */
89 #define STM32_MBR_DIV_MIN	(2 << SPI_CFG1_MBR_MIN)
90 #define STM32_MBR_DIV_MAX	(2 << SPI_CFG1_MBR_MAX)
91 
92 #define STM32_SPI_TIMEOUT_US	100000
93 
94 /* SPI Communication mode */
95 #define SPI_FULL_DUPLEX		0
96 #define SPI_SIMPLEX_TX		1
97 #define SPI_SIMPLEX_RX		2
98 #define SPI_HALF_DUPLEX		3
99 
100 struct stm32_spi_priv {
101 	void __iomem *base;
102 	struct clk clk;
103 	struct reset_ctl rst_ctl;
104 	struct gpio_desc cs_gpios[MAX_CS_COUNT];
105 	ulong bus_clk_rate;
106 	unsigned int fifo_size;
107 	unsigned int cur_bpw;
108 	unsigned int cur_hz;
109 	unsigned int cur_xferlen; /* current transfer length in bytes */
110 	unsigned int tx_len;	  /* number of data to be written in bytes */
111 	unsigned int rx_len;	  /* number of data to be read in bytes */
112 	const void *tx_buf;	  /* data to be written, or NULL */
113 	void *rx_buf;		  /* data to be read, or NULL */
114 	u32 cur_mode;
115 	bool cs_high;
116 };
117 
stm32_spi_write_txfifo(struct stm32_spi_priv * priv)118 static void stm32_spi_write_txfifo(struct stm32_spi_priv *priv)
119 {
120 	while ((priv->tx_len > 0) &&
121 	       (readl(priv->base + STM32_SPI_SR) & SPI_SR_TXP)) {
122 		u32 offs = priv->cur_xferlen - priv->tx_len;
123 
124 		if (priv->tx_len >= sizeof(u32) &&
125 		    IS_ALIGNED((uintptr_t)(priv->tx_buf + offs), sizeof(u32))) {
126 			const u32 *tx_buf32 = (const u32 *)(priv->tx_buf + offs);
127 
128 			writel(*tx_buf32, priv->base + STM32_SPI_TXDR);
129 			priv->tx_len -= sizeof(u32);
130 		} else if (priv->tx_len >= sizeof(u16) &&
131 			   IS_ALIGNED((uintptr_t)(priv->tx_buf + offs), sizeof(u16))) {
132 			const u16 *tx_buf16 = (const u16 *)(priv->tx_buf + offs);
133 
134 			writew(*tx_buf16, priv->base + STM32_SPI_TXDR);
135 			priv->tx_len -= sizeof(u16);
136 		} else {
137 			const u8 *tx_buf8 = (const u8 *)(priv->tx_buf + offs);
138 
139 			writeb(*tx_buf8, priv->base + STM32_SPI_TXDR);
140 			priv->tx_len -= sizeof(u8);
141 		}
142 	}
143 
144 	log_debug("%d bytes left\n", priv->tx_len);
145 }
146 
stm32_spi_read_rxfifo(struct stm32_spi_priv * priv)147 static void stm32_spi_read_rxfifo(struct stm32_spi_priv *priv)
148 {
149 	u32 sr = readl(priv->base + STM32_SPI_SR);
150 	u32 rxplvl = (sr & SPI_SR_RXPLVL) >> SPI_SR_RXPLVL_SHIFT;
151 
152 	while ((priv->rx_len > 0) &&
153 	       ((sr & SPI_SR_RXP) ||
154 	       ((sr & SPI_SR_EOT) && ((sr & SPI_SR_RXWNE) || (rxplvl > 0))))) {
155 		u32 offs = priv->cur_xferlen - priv->rx_len;
156 
157 		if (IS_ALIGNED((uintptr_t)(priv->rx_buf + offs), sizeof(u32)) &&
158 		    (priv->rx_len >= sizeof(u32) || (sr & SPI_SR_RXWNE))) {
159 			u32 *rx_buf32 = (u32 *)(priv->rx_buf + offs);
160 
161 			*rx_buf32 = readl(priv->base + STM32_SPI_RXDR);
162 			priv->rx_len -= sizeof(u32);
163 		} else if (IS_ALIGNED((uintptr_t)(priv->rx_buf + offs), sizeof(u16)) &&
164 			   (priv->rx_len >= sizeof(u16) ||
165 			    (!(sr & SPI_SR_RXWNE) &&
166 			    (rxplvl >= 2 || priv->cur_bpw > 8)))) {
167 			u16 *rx_buf16 = (u16 *)(priv->rx_buf + offs);
168 
169 			*rx_buf16 = readw(priv->base + STM32_SPI_RXDR);
170 			priv->rx_len -= sizeof(u16);
171 		} else {
172 			u8 *rx_buf8 = (u8 *)(priv->rx_buf + offs);
173 
174 			*rx_buf8 = readb(priv->base + STM32_SPI_RXDR);
175 			priv->rx_len -= sizeof(u8);
176 		}
177 
178 		sr = readl(priv->base + STM32_SPI_SR);
179 		rxplvl = (sr & SPI_SR_RXPLVL) >> SPI_SR_RXPLVL_SHIFT;
180 	}
181 
182 	log_debug("%d bytes left\n", priv->rx_len);
183 }
184 
stm32_spi_enable(struct stm32_spi_priv * priv)185 static int stm32_spi_enable(struct stm32_spi_priv *priv)
186 {
187 	log_debug("\n");
188 
189 	/* Enable the SPI hardware */
190 	setbits_le32(priv->base + STM32_SPI_CR1, SPI_CR1_SPE);
191 
192 	return 0;
193 }
194 
stm32_spi_disable(struct stm32_spi_priv * priv)195 static int stm32_spi_disable(struct stm32_spi_priv *priv)
196 {
197 	log_debug("\n");
198 
199 	/* Disable the SPI hardware */
200 	clrbits_le32(priv->base + STM32_SPI_CR1, SPI_CR1_SPE);
201 
202 	return 0;
203 }
204 
stm32_spi_claim_bus(struct udevice * slave)205 static int stm32_spi_claim_bus(struct udevice *slave)
206 {
207 	struct udevice *bus = dev_get_parent(slave);
208 	struct stm32_spi_priv *priv = dev_get_priv(bus);
209 
210 	dev_dbg(slave, "\n");
211 
212 	/* Enable the SPI hardware */
213 	return stm32_spi_enable(priv);
214 }
215 
stm32_spi_release_bus(struct udevice * slave)216 static int stm32_spi_release_bus(struct udevice *slave)
217 {
218 	struct udevice *bus = dev_get_parent(slave);
219 	struct stm32_spi_priv *priv = dev_get_priv(bus);
220 
221 	dev_dbg(slave, "\n");
222 
223 	/* Disable the SPI hardware */
224 	return stm32_spi_disable(priv);
225 }
226 
stm32_spi_stopxfer(struct udevice * dev)227 static void stm32_spi_stopxfer(struct udevice *dev)
228 {
229 	struct stm32_spi_priv *priv = dev_get_priv(dev);
230 	u32 cr1, sr;
231 	int ret;
232 
233 	dev_dbg(dev, "\n");
234 
235 	cr1 = readl(priv->base + STM32_SPI_CR1);
236 
237 	if (!(cr1 & SPI_CR1_SPE))
238 		return;
239 
240 	/* Wait on EOT or suspend the flow */
241 	ret = readl_poll_timeout(priv->base + STM32_SPI_SR, sr,
242 				 !(sr & SPI_SR_EOT), 100000);
243 	if (ret < 0) {
244 		if (cr1 & SPI_CR1_CSTART) {
245 			writel(cr1 | SPI_CR1_CSUSP, priv->base + STM32_SPI_CR1);
246 			if (readl_poll_timeout(priv->base + STM32_SPI_SR,
247 					       sr, !(sr & SPI_SR_SUSP),
248 					       100000) < 0)
249 				dev_err(dev, "Suspend request timeout\n");
250 		}
251 	}
252 
253 	/* clear status flags */
254 	setbits_le32(priv->base + STM32_SPI_IFCR, SPI_IFCR_ALL);
255 }
256 
stm32_spi_set_cs(struct udevice * dev,unsigned int cs,bool enable)257 static int stm32_spi_set_cs(struct udevice *dev, unsigned int cs, bool enable)
258 {
259 	struct stm32_spi_priv *priv = dev_get_priv(dev);
260 
261 	dev_dbg(dev, "cs=%d enable=%d\n", cs, enable);
262 
263 	if (cs >= MAX_CS_COUNT)
264 		return -ENODEV;
265 
266 	if (!dm_gpio_is_valid(&priv->cs_gpios[cs]))
267 		return -EINVAL;
268 
269 	if (priv->cs_high)
270 		enable = !enable;
271 
272 	return dm_gpio_set_value(&priv->cs_gpios[cs], enable ? 1 : 0);
273 }
274 
stm32_spi_set_mode(struct udevice * bus,uint mode)275 static int stm32_spi_set_mode(struct udevice *bus, uint mode)
276 {
277 	struct stm32_spi_priv *priv = dev_get_priv(bus);
278 	u32 cfg2_clrb = 0, cfg2_setb = 0;
279 
280 	dev_dbg(bus, "mode=%d\n", mode);
281 
282 	if (mode & SPI_CPOL)
283 		cfg2_setb |= SPI_CFG2_CPOL;
284 	else
285 		cfg2_clrb |= SPI_CFG2_CPOL;
286 
287 	if (mode & SPI_CPHA)
288 		cfg2_setb |= SPI_CFG2_CPHA;
289 	else
290 		cfg2_clrb |= SPI_CFG2_CPHA;
291 
292 	if (mode & SPI_LSB_FIRST)
293 		cfg2_setb |= SPI_CFG2_LSBFRST;
294 	else
295 		cfg2_clrb |= SPI_CFG2_LSBFRST;
296 
297 	if (cfg2_clrb || cfg2_setb)
298 		clrsetbits_le32(priv->base + STM32_SPI_CFG2,
299 				cfg2_clrb, cfg2_setb);
300 
301 	if (mode & SPI_CS_HIGH)
302 		priv->cs_high = true;
303 	else
304 		priv->cs_high = false;
305 	return 0;
306 }
307 
stm32_spi_set_fthlv(struct udevice * dev,u32 xfer_len)308 static int stm32_spi_set_fthlv(struct udevice *dev, u32 xfer_len)
309 {
310 	struct stm32_spi_priv *priv = dev_get_priv(dev);
311 	u32 fthlv, half_fifo;
312 
313 	/* data packet should not exceed 1/2 of fifo space */
314 	half_fifo = (priv->fifo_size / 2);
315 
316 	/* data_packet should not exceed transfer length */
317 	fthlv = (half_fifo > xfer_len) ? xfer_len : half_fifo;
318 
319 	/* align packet size with data registers access */
320 	fthlv -= (fthlv % 4);
321 
322 	if (!fthlv)
323 		fthlv = 1;
324 	clrsetbits_le32(priv->base + STM32_SPI_CFG1, SPI_CFG1_FTHLV,
325 			(fthlv - 1) << SPI_CFG1_FTHLV_SHIFT);
326 
327 	return 0;
328 }
329 
stm32_spi_set_speed(struct udevice * bus,uint hz)330 static int stm32_spi_set_speed(struct udevice *bus, uint hz)
331 {
332 	struct stm32_spi_priv *priv = dev_get_priv(bus);
333 	u32 mbrdiv;
334 	long div;
335 
336 	dev_dbg(bus, "hz=%d\n", hz);
337 
338 	if (priv->cur_hz == hz)
339 		return 0;
340 
341 	div = DIV_ROUND_UP(priv->bus_clk_rate, hz);
342 
343 	if (div < STM32_MBR_DIV_MIN ||
344 	    div > STM32_MBR_DIV_MAX)
345 		return -EINVAL;
346 
347 	/* Determine the first power of 2 greater than or equal to div */
348 	if (div & (div - 1))
349 		mbrdiv = fls(div);
350 	else
351 		mbrdiv = fls(div) - 1;
352 
353 	if (!mbrdiv)
354 		return -EINVAL;
355 
356 	clrsetbits_le32(priv->base + STM32_SPI_CFG1, SPI_CFG1_MBR,
357 			(mbrdiv - 1) << SPI_CFG1_MBR_SHIFT);
358 
359 	priv->cur_hz = hz;
360 
361 	return 0;
362 }
363 
stm32_spi_xfer(struct udevice * slave,unsigned int bitlen,const void * dout,void * din,unsigned long flags)364 static int stm32_spi_xfer(struct udevice *slave, unsigned int bitlen,
365 			  const void *dout, void *din, unsigned long flags)
366 {
367 	struct udevice *bus = dev_get_parent(slave);
368 	struct dm_spi_slave_plat *slave_plat;
369 	struct stm32_spi_priv *priv = dev_get_priv(bus);
370 	u32 sr;
371 	u32 ifcr = 0;
372 	u32 xferlen;
373 	u32 mode;
374 	int xfer_status = 0;
375 
376 	xferlen = bitlen / 8;
377 
378 	if (xferlen <= SPI_CR2_TSIZE)
379 		writel(xferlen, priv->base + STM32_SPI_CR2);
380 	else
381 		return -EMSGSIZE;
382 
383 	priv->tx_buf = dout;
384 	priv->rx_buf = din;
385 	priv->tx_len = priv->tx_buf ? bitlen / 8 : 0;
386 	priv->rx_len = priv->rx_buf ? bitlen / 8 : 0;
387 
388 	mode = SPI_FULL_DUPLEX;
389 	if (!priv->tx_buf)
390 		mode = SPI_SIMPLEX_RX;
391 	else if (!priv->rx_buf)
392 		mode = SPI_SIMPLEX_TX;
393 
394 	if (priv->cur_xferlen != xferlen || priv->cur_mode != mode) {
395 		priv->cur_mode = mode;
396 		priv->cur_xferlen = xferlen;
397 
398 		/* Disable the SPI hardware to unlock CFG1/CFG2 registers */
399 		stm32_spi_disable(priv);
400 
401 		clrsetbits_le32(priv->base + STM32_SPI_CFG2, SPI_CFG2_COMM,
402 				mode << SPI_CFG2_COMM_SHIFT);
403 
404 		stm32_spi_set_fthlv(bus, xferlen);
405 
406 		/* Enable the SPI hardware */
407 		stm32_spi_enable(priv);
408 	}
409 
410 	dev_dbg(bus, "priv->tx_len=%d priv->rx_len=%d\n",
411 		priv->tx_len, priv->rx_len);
412 
413 	slave_plat = dev_get_parent_plat(slave);
414 	if (flags & SPI_XFER_BEGIN)
415 		stm32_spi_set_cs(bus, slave_plat->cs, false);
416 
417 	/* Be sure to have data in fifo before starting data transfer */
418 	if (priv->tx_buf)
419 		stm32_spi_write_txfifo(priv);
420 
421 	setbits_le32(priv->base + STM32_SPI_CR1, SPI_CR1_CSTART);
422 
423 	while (1) {
424 		sr = readl(priv->base + STM32_SPI_SR);
425 
426 		if (sr & SPI_SR_OVR) {
427 			dev_err(bus, "Overrun: RX data lost\n");
428 			xfer_status = -EIO;
429 			break;
430 		}
431 
432 		if (sr & SPI_SR_SUSP) {
433 			dev_warn(bus, "System too slow is limiting data throughput\n");
434 
435 			if (priv->rx_buf && priv->rx_len > 0)
436 				stm32_spi_read_rxfifo(priv);
437 
438 			ifcr |= SPI_SR_SUSP;
439 		}
440 
441 		if (sr & SPI_SR_TXTF)
442 			ifcr |= SPI_SR_TXTF;
443 
444 		if (sr & SPI_SR_TXP)
445 			if (priv->tx_buf && priv->tx_len > 0)
446 				stm32_spi_write_txfifo(priv);
447 
448 		if (sr & SPI_SR_RXP)
449 			if (priv->rx_buf && priv->rx_len > 0)
450 				stm32_spi_read_rxfifo(priv);
451 
452 		if (sr & SPI_SR_EOT) {
453 			if (priv->rx_buf && priv->rx_len > 0)
454 				stm32_spi_read_rxfifo(priv);
455 			break;
456 		}
457 
458 		writel(ifcr, priv->base + STM32_SPI_IFCR);
459 	}
460 
461 	/* clear status flags */
462 	setbits_le32(priv->base + STM32_SPI_IFCR, SPI_IFCR_ALL);
463 	stm32_spi_stopxfer(bus);
464 
465 	if (flags & SPI_XFER_END)
466 		stm32_spi_set_cs(bus, slave_plat->cs, true);
467 
468 	return xfer_status;
469 }
470 
stm32_spi_get_fifo_size(struct udevice * dev)471 static int stm32_spi_get_fifo_size(struct udevice *dev)
472 {
473 	struct stm32_spi_priv *priv = dev_get_priv(dev);
474 	u32 count = 0;
475 
476 	stm32_spi_enable(priv);
477 
478 	while (readl(priv->base + STM32_SPI_SR) & SPI_SR_TXP)
479 		writeb(++count, priv->base + STM32_SPI_TXDR);
480 
481 	stm32_spi_disable(priv);
482 
483 	dev_dbg(dev, "%d x 8-bit fifo size\n", count);
484 
485 	return count;
486 }
487 
stm32_spi_probe(struct udevice * dev)488 static int stm32_spi_probe(struct udevice *dev)
489 {
490 	struct stm32_spi_priv *priv = dev_get_priv(dev);
491 	unsigned long clk_rate;
492 	int ret;
493 	unsigned int i;
494 
495 	priv->base = dev_remap_addr(dev);
496 	if (!priv->base)
497 		return -EINVAL;
498 
499 	/* enable clock */
500 	ret = clk_get_by_index(dev, 0, &priv->clk);
501 	if (ret < 0)
502 		return ret;
503 
504 	ret = clk_enable(&priv->clk);
505 	if (ret < 0)
506 		return ret;
507 
508 	clk_rate = clk_get_rate(&priv->clk);
509 	if (!clk_rate) {
510 		ret = -EINVAL;
511 		goto clk_err;
512 	}
513 
514 	priv->bus_clk_rate = clk_rate;
515 
516 	/* perform reset */
517 	ret = reset_get_by_index(dev, 0, &priv->rst_ctl);
518 	if (ret < 0)
519 		goto clk_err;
520 
521 	reset_assert(&priv->rst_ctl);
522 	udelay(2);
523 	reset_deassert(&priv->rst_ctl);
524 
525 	ret = gpio_request_list_by_name(dev, "cs-gpios", priv->cs_gpios,
526 					ARRAY_SIZE(priv->cs_gpios), 0);
527 	if (ret < 0) {
528 		dev_err(dev, "Can't get cs gpios: %d", ret);
529 		goto reset_err;
530 	}
531 
532 	priv->fifo_size = stm32_spi_get_fifo_size(dev);
533 
534 	priv->cur_mode = SPI_FULL_DUPLEX;
535 	priv->cur_xferlen = 0;
536 	priv->cur_bpw = SPI_DEFAULT_WORDLEN;
537 	clrsetbits_le32(priv->base + STM32_SPI_CFG1, SPI_CFG1_DSIZE,
538 			priv->cur_bpw - 1);
539 
540 	for (i = 0; i < ARRAY_SIZE(priv->cs_gpios); i++) {
541 		if (!dm_gpio_is_valid(&priv->cs_gpios[i]))
542 			continue;
543 
544 		dm_gpio_set_dir_flags(&priv->cs_gpios[i],
545 				      GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
546 	}
547 
548 	/* Ensure I2SMOD bit is kept cleared */
549 	clrbits_le32(priv->base + STM32_SPI_I2SCFGR, SPI_I2SCFGR_I2SMOD);
550 
551 	/*
552 	 * - SS input value high
553 	 * - transmitter half duplex direction
554 	 * - automatic communication suspend when RX-Fifo is full
555 	 */
556 	setbits_le32(priv->base + STM32_SPI_CR1,
557 		     SPI_CR1_SSI | SPI_CR1_HDDIR | SPI_CR1_MASRX);
558 
559 	/*
560 	 * - Set the master mode (default Motorola mode)
561 	 * - Consider 1 master/n slaves configuration and
562 	 *   SS input value is determined by the SSI bit
563 	 * - keep control of all associated GPIOs
564 	 */
565 	setbits_le32(priv->base + STM32_SPI_CFG2,
566 		     SPI_CFG2_MASTER | SPI_CFG2_SSM | SPI_CFG2_AFCNTR);
567 
568 	return 0;
569 
570 reset_err:
571 	reset_free(&priv->rst_ctl);
572 
573 clk_err:
574 	clk_disable(&priv->clk);
575 	clk_free(&priv->clk);
576 
577 	return ret;
578 };
579 
stm32_spi_remove(struct udevice * dev)580 static int stm32_spi_remove(struct udevice *dev)
581 {
582 	struct stm32_spi_priv *priv = dev_get_priv(dev);
583 	int ret;
584 
585 	stm32_spi_stopxfer(dev);
586 	stm32_spi_disable(priv);
587 
588 	ret = reset_assert(&priv->rst_ctl);
589 	if (ret < 0)
590 		return ret;
591 
592 	reset_free(&priv->rst_ctl);
593 
594 	ret = clk_disable(&priv->clk);
595 	if (ret < 0)
596 		return ret;
597 
598 	clk_free(&priv->clk);
599 
600 	return ret;
601 };
602 
603 static const struct dm_spi_ops stm32_spi_ops = {
604 	.claim_bus	= stm32_spi_claim_bus,
605 	.release_bus	= stm32_spi_release_bus,
606 	.set_mode	= stm32_spi_set_mode,
607 	.set_speed	= stm32_spi_set_speed,
608 	.xfer		= stm32_spi_xfer,
609 };
610 
611 static const struct udevice_id stm32_spi_ids[] = {
612 	{ .compatible = "st,stm32h7-spi", },
613 	{ }
614 };
615 
616 U_BOOT_DRIVER(stm32_spi) = {
617 	.name			= "stm32_spi",
618 	.id			= UCLASS_SPI,
619 	.of_match		= stm32_spi_ids,
620 	.ops			= &stm32_spi_ops,
621 	.priv_auto	= sizeof(struct stm32_spi_priv),
622 	.probe			= stm32_spi_probe,
623 	.remove			= stm32_spi_remove,
624 };
625