xref: /linux/drivers/spi/spi-stm32-qspi.c (revision 37744feebc086908fd89760650f458ab19071750)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) STMicroelectronics 2018 - All Rights Reserved
4  * Author: Ludovic Barre <ludovic.barre@st.com> for STMicroelectronics.
5  */
6 #include <linux/bitfield.h>
7 #include <linux/clk.h>
8 #include <linux/dmaengine.h>
9 #include <linux/dma-mapping.h>
10 #include <linux/errno.h>
11 #include <linux/io.h>
12 #include <linux/iopoll.h>
13 #include <linux/interrupt.h>
14 #include <linux/module.h>
15 #include <linux/mutex.h>
16 #include <linux/of.h>
17 #include <linux/of_device.h>
18 #include <linux/pinctrl/consumer.h>
19 #include <linux/platform_device.h>
20 #include <linux/reset.h>
21 #include <linux/sizes.h>
22 #include <linux/spi/spi-mem.h>
23 
24 #define QSPI_CR			0x00
25 #define CR_EN			BIT(0)
26 #define CR_ABORT		BIT(1)
27 #define CR_DMAEN		BIT(2)
28 #define CR_TCEN			BIT(3)
29 #define CR_SSHIFT		BIT(4)
30 #define CR_DFM			BIT(6)
31 #define CR_FSEL			BIT(7)
32 #define CR_FTHRES_SHIFT		8
33 #define CR_TEIE			BIT(16)
34 #define CR_TCIE			BIT(17)
35 #define CR_FTIE			BIT(18)
36 #define CR_SMIE			BIT(19)
37 #define CR_TOIE			BIT(20)
38 #define CR_PRESC_MASK		GENMASK(31, 24)
39 
40 #define QSPI_DCR		0x04
41 #define DCR_FSIZE_MASK		GENMASK(20, 16)
42 
43 #define QSPI_SR			0x08
44 #define SR_TEF			BIT(0)
45 #define SR_TCF			BIT(1)
46 #define SR_FTF			BIT(2)
47 #define SR_SMF			BIT(3)
48 #define SR_TOF			BIT(4)
49 #define SR_BUSY			BIT(5)
50 #define SR_FLEVEL_MASK		GENMASK(13, 8)
51 
52 #define QSPI_FCR		0x0c
53 #define FCR_CTEF		BIT(0)
54 #define FCR_CTCF		BIT(1)
55 
56 #define QSPI_DLR		0x10
57 
58 #define QSPI_CCR		0x14
59 #define CCR_INST_MASK		GENMASK(7, 0)
60 #define CCR_IMODE_MASK		GENMASK(9, 8)
61 #define CCR_ADMODE_MASK		GENMASK(11, 10)
62 #define CCR_ADSIZE_MASK		GENMASK(13, 12)
63 #define CCR_DCYC_MASK		GENMASK(22, 18)
64 #define CCR_DMODE_MASK		GENMASK(25, 24)
65 #define CCR_FMODE_MASK		GENMASK(27, 26)
66 #define CCR_FMODE_INDW		(0U << 26)
67 #define CCR_FMODE_INDR		(1U << 26)
68 #define CCR_FMODE_APM		(2U << 26)
69 #define CCR_FMODE_MM		(3U << 26)
70 #define CCR_BUSWIDTH_0		0x0
71 #define CCR_BUSWIDTH_1		0x1
72 #define CCR_BUSWIDTH_2		0x2
73 #define CCR_BUSWIDTH_4		0x3
74 
75 #define QSPI_AR			0x18
76 #define QSPI_ABR		0x1c
77 #define QSPI_DR			0x20
78 #define QSPI_PSMKR		0x24
79 #define QSPI_PSMAR		0x28
80 #define QSPI_PIR		0x2c
81 #define QSPI_LPTR		0x30
82 
83 #define STM32_QSPI_MAX_MMAP_SZ	SZ_256M
84 #define STM32_QSPI_MAX_NORCHIP	2
85 
86 #define STM32_FIFO_TIMEOUT_US 30000
87 #define STM32_BUSY_TIMEOUT_US 100000
88 #define STM32_ABT_TIMEOUT_US 100000
89 #define STM32_COMP_TIMEOUT_MS 1000
90 
91 struct stm32_qspi_flash {
92 	struct stm32_qspi *qspi;
93 	u32 cs;
94 	u32 presc;
95 };
96 
97 struct stm32_qspi {
98 	struct device *dev;
99 	struct spi_controller *ctrl;
100 	phys_addr_t phys_base;
101 	void __iomem *io_base;
102 	void __iomem *mm_base;
103 	resource_size_t mm_size;
104 	struct clk *clk;
105 	u32 clk_rate;
106 	struct stm32_qspi_flash flash[STM32_QSPI_MAX_NORCHIP];
107 	struct completion data_completion;
108 	u32 fmode;
109 
110 	struct dma_chan *dma_chtx;
111 	struct dma_chan *dma_chrx;
112 	struct completion dma_completion;
113 
114 	u32 cr_reg;
115 	u32 dcr_reg;
116 
117 	/*
118 	 * to protect device configuration, could be different between
119 	 * 2 flash access (bk1, bk2)
120 	 */
121 	struct mutex lock;
122 };
123 
124 static irqreturn_t stm32_qspi_irq(int irq, void *dev_id)
125 {
126 	struct stm32_qspi *qspi = (struct stm32_qspi *)dev_id;
127 	u32 cr, sr;
128 
129 	sr = readl_relaxed(qspi->io_base + QSPI_SR);
130 
131 	if (sr & (SR_TEF | SR_TCF)) {
132 		/* disable irq */
133 		cr = readl_relaxed(qspi->io_base + QSPI_CR);
134 		cr &= ~CR_TCIE & ~CR_TEIE;
135 		writel_relaxed(cr, qspi->io_base + QSPI_CR);
136 		complete(&qspi->data_completion);
137 	}
138 
139 	return IRQ_HANDLED;
140 }
141 
142 static void stm32_qspi_read_fifo(u8 *val, void __iomem *addr)
143 {
144 	*val = readb_relaxed(addr);
145 }
146 
147 static void stm32_qspi_write_fifo(u8 *val, void __iomem *addr)
148 {
149 	writeb_relaxed(*val, addr);
150 }
151 
152 static int stm32_qspi_tx_poll(struct stm32_qspi *qspi,
153 			      const struct spi_mem_op *op)
154 {
155 	void (*tx_fifo)(u8 *val, void __iomem *addr);
156 	u32 len = op->data.nbytes, sr;
157 	u8 *buf;
158 	int ret;
159 
160 	if (op->data.dir == SPI_MEM_DATA_IN) {
161 		tx_fifo = stm32_qspi_read_fifo;
162 		buf = op->data.buf.in;
163 
164 	} else {
165 		tx_fifo = stm32_qspi_write_fifo;
166 		buf = (u8 *)op->data.buf.out;
167 	}
168 
169 	while (len--) {
170 		ret = readl_relaxed_poll_timeout_atomic(qspi->io_base + QSPI_SR,
171 							sr, (sr & SR_FTF), 1,
172 							STM32_FIFO_TIMEOUT_US);
173 		if (ret) {
174 			dev_err(qspi->dev, "fifo timeout (len:%d stat:%#x)\n",
175 				len, sr);
176 			return ret;
177 		}
178 		tx_fifo(buf++, qspi->io_base + QSPI_DR);
179 	}
180 
181 	return 0;
182 }
183 
184 static int stm32_qspi_tx_mm(struct stm32_qspi *qspi,
185 			    const struct spi_mem_op *op)
186 {
187 	memcpy_fromio(op->data.buf.in, qspi->mm_base + op->addr.val,
188 		      op->data.nbytes);
189 	return 0;
190 }
191 
192 static void stm32_qspi_dma_callback(void *arg)
193 {
194 	struct completion *dma_completion = arg;
195 
196 	complete(dma_completion);
197 }
198 
199 static int stm32_qspi_tx_dma(struct stm32_qspi *qspi,
200 			     const struct spi_mem_op *op)
201 {
202 	struct dma_async_tx_descriptor *desc;
203 	enum dma_transfer_direction dma_dir;
204 	struct dma_chan *dma_ch;
205 	struct sg_table sgt;
206 	dma_cookie_t cookie;
207 	u32 cr, t_out;
208 	int err;
209 
210 	if (op->data.dir == SPI_MEM_DATA_IN) {
211 		dma_dir = DMA_DEV_TO_MEM;
212 		dma_ch = qspi->dma_chrx;
213 	} else {
214 		dma_dir = DMA_MEM_TO_DEV;
215 		dma_ch = qspi->dma_chtx;
216 	}
217 
218 	/*
219 	 * spi_map_buf return -EINVAL if the buffer is not DMA-able
220 	 * (DMA-able: in vmalloc | kmap | virt_addr_valid)
221 	 */
222 	err = spi_controller_dma_map_mem_op_data(qspi->ctrl, op, &sgt);
223 	if (err)
224 		return err;
225 
226 	desc = dmaengine_prep_slave_sg(dma_ch, sgt.sgl, sgt.nents,
227 				       dma_dir, DMA_PREP_INTERRUPT);
228 	if (!desc) {
229 		err = -ENOMEM;
230 		goto out_unmap;
231 	}
232 
233 	cr = readl_relaxed(qspi->io_base + QSPI_CR);
234 
235 	reinit_completion(&qspi->dma_completion);
236 	desc->callback = stm32_qspi_dma_callback;
237 	desc->callback_param = &qspi->dma_completion;
238 	cookie = dmaengine_submit(desc);
239 	err = dma_submit_error(cookie);
240 	if (err)
241 		goto out;
242 
243 	dma_async_issue_pending(dma_ch);
244 
245 	writel_relaxed(cr | CR_DMAEN, qspi->io_base + QSPI_CR);
246 
247 	t_out = sgt.nents * STM32_COMP_TIMEOUT_MS;
248 	if (!wait_for_completion_timeout(&qspi->dma_completion,
249 					 msecs_to_jiffies(t_out)))
250 		err = -ETIMEDOUT;
251 
252 	if (err)
253 		dmaengine_terminate_all(dma_ch);
254 
255 out:
256 	writel_relaxed(cr & ~CR_DMAEN, qspi->io_base + QSPI_CR);
257 out_unmap:
258 	spi_controller_dma_unmap_mem_op_data(qspi->ctrl, op, &sgt);
259 
260 	return err;
261 }
262 
263 static int stm32_qspi_tx(struct stm32_qspi *qspi, const struct spi_mem_op *op)
264 {
265 	if (!op->data.nbytes)
266 		return 0;
267 
268 	if (qspi->fmode == CCR_FMODE_MM)
269 		return stm32_qspi_tx_mm(qspi, op);
270 	else if ((op->data.dir == SPI_MEM_DATA_IN && qspi->dma_chrx) ||
271 		 (op->data.dir == SPI_MEM_DATA_OUT && qspi->dma_chtx))
272 		if (!stm32_qspi_tx_dma(qspi, op))
273 			return 0;
274 
275 	return stm32_qspi_tx_poll(qspi, op);
276 }
277 
278 static int stm32_qspi_wait_nobusy(struct stm32_qspi *qspi)
279 {
280 	u32 sr;
281 
282 	return readl_relaxed_poll_timeout_atomic(qspi->io_base + QSPI_SR, sr,
283 						 !(sr & SR_BUSY), 1,
284 						 STM32_BUSY_TIMEOUT_US);
285 }
286 
287 static int stm32_qspi_wait_cmd(struct stm32_qspi *qspi,
288 			       const struct spi_mem_op *op)
289 {
290 	u32 cr, sr;
291 	int err = 0;
292 
293 	if (!op->data.nbytes)
294 		return stm32_qspi_wait_nobusy(qspi);
295 
296 	if (readl_relaxed(qspi->io_base + QSPI_SR) & SR_TCF)
297 		goto out;
298 
299 	reinit_completion(&qspi->data_completion);
300 	cr = readl_relaxed(qspi->io_base + QSPI_CR);
301 	writel_relaxed(cr | CR_TCIE | CR_TEIE, qspi->io_base + QSPI_CR);
302 
303 	if (!wait_for_completion_timeout(&qspi->data_completion,
304 				msecs_to_jiffies(STM32_COMP_TIMEOUT_MS))) {
305 		err = -ETIMEDOUT;
306 	} else {
307 		sr = readl_relaxed(qspi->io_base + QSPI_SR);
308 		if (sr & SR_TEF)
309 			err = -EIO;
310 	}
311 
312 out:
313 	/* clear flags */
314 	writel_relaxed(FCR_CTCF | FCR_CTEF, qspi->io_base + QSPI_FCR);
315 
316 	return err;
317 }
318 
319 static int stm32_qspi_get_mode(struct stm32_qspi *qspi, u8 buswidth)
320 {
321 	if (buswidth == 4)
322 		return CCR_BUSWIDTH_4;
323 
324 	return buswidth;
325 }
326 
327 static int stm32_qspi_send(struct spi_mem *mem, const struct spi_mem_op *op)
328 {
329 	struct stm32_qspi *qspi = spi_controller_get_devdata(mem->spi->master);
330 	struct stm32_qspi_flash *flash = &qspi->flash[mem->spi->chip_select];
331 	u32 ccr, cr, addr_max;
332 	int timeout, err = 0;
333 
334 	dev_dbg(qspi->dev, "cmd:%#x mode:%d.%d.%d.%d addr:%#llx len:%#x\n",
335 		op->cmd.opcode, op->cmd.buswidth, op->addr.buswidth,
336 		op->dummy.buswidth, op->data.buswidth,
337 		op->addr.val, op->data.nbytes);
338 
339 	err = stm32_qspi_wait_nobusy(qspi);
340 	if (err)
341 		goto abort;
342 
343 	addr_max = op->addr.val + op->data.nbytes + 1;
344 
345 	if (op->data.dir == SPI_MEM_DATA_IN) {
346 		if (addr_max < qspi->mm_size &&
347 		    op->addr.buswidth)
348 			qspi->fmode = CCR_FMODE_MM;
349 		else
350 			qspi->fmode = CCR_FMODE_INDR;
351 	} else {
352 		qspi->fmode = CCR_FMODE_INDW;
353 	}
354 
355 	cr = readl_relaxed(qspi->io_base + QSPI_CR);
356 	cr &= ~CR_PRESC_MASK & ~CR_FSEL;
357 	cr |= FIELD_PREP(CR_PRESC_MASK, flash->presc);
358 	cr |= FIELD_PREP(CR_FSEL, flash->cs);
359 	writel_relaxed(cr, qspi->io_base + QSPI_CR);
360 
361 	if (op->data.nbytes)
362 		writel_relaxed(op->data.nbytes - 1,
363 			       qspi->io_base + QSPI_DLR);
364 	else
365 		qspi->fmode = CCR_FMODE_INDW;
366 
367 	ccr = qspi->fmode;
368 	ccr |= FIELD_PREP(CCR_INST_MASK, op->cmd.opcode);
369 	ccr |= FIELD_PREP(CCR_IMODE_MASK,
370 			  stm32_qspi_get_mode(qspi, op->cmd.buswidth));
371 
372 	if (op->addr.nbytes) {
373 		ccr |= FIELD_PREP(CCR_ADMODE_MASK,
374 				  stm32_qspi_get_mode(qspi, op->addr.buswidth));
375 		ccr |= FIELD_PREP(CCR_ADSIZE_MASK, op->addr.nbytes - 1);
376 	}
377 
378 	if (op->dummy.buswidth && op->dummy.nbytes)
379 		ccr |= FIELD_PREP(CCR_DCYC_MASK,
380 				  op->dummy.nbytes * 8 / op->dummy.buswidth);
381 
382 	if (op->data.nbytes) {
383 		ccr |= FIELD_PREP(CCR_DMODE_MASK,
384 				  stm32_qspi_get_mode(qspi, op->data.buswidth));
385 	}
386 
387 	writel_relaxed(ccr, qspi->io_base + QSPI_CCR);
388 
389 	if (op->addr.nbytes && qspi->fmode != CCR_FMODE_MM)
390 		writel_relaxed(op->addr.val, qspi->io_base + QSPI_AR);
391 
392 	err = stm32_qspi_tx(qspi, op);
393 
394 	/*
395 	 * Abort in:
396 	 * -error case
397 	 * -read memory map: prefetching must be stopped if we read the last
398 	 *  byte of device (device size - fifo size). like device size is not
399 	 *  knows, the prefetching is always stop.
400 	 */
401 	if (err || qspi->fmode == CCR_FMODE_MM)
402 		goto abort;
403 
404 	/* wait end of tx in indirect mode */
405 	err = stm32_qspi_wait_cmd(qspi, op);
406 	if (err)
407 		goto abort;
408 
409 	return 0;
410 
411 abort:
412 	cr = readl_relaxed(qspi->io_base + QSPI_CR) | CR_ABORT;
413 	writel_relaxed(cr, qspi->io_base + QSPI_CR);
414 
415 	/* wait clear of abort bit by hw */
416 	timeout = readl_relaxed_poll_timeout_atomic(qspi->io_base + QSPI_CR,
417 						    cr, !(cr & CR_ABORT), 1,
418 						    STM32_ABT_TIMEOUT_US);
419 
420 	writel_relaxed(FCR_CTCF, qspi->io_base + QSPI_FCR);
421 
422 	if (err || timeout)
423 		dev_err(qspi->dev, "%s err:%d abort timeout:%d\n",
424 			__func__, err, timeout);
425 
426 	return err;
427 }
428 
429 static int stm32_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
430 {
431 	struct stm32_qspi *qspi = spi_controller_get_devdata(mem->spi->master);
432 	int ret;
433 
434 	mutex_lock(&qspi->lock);
435 	ret = stm32_qspi_send(mem, op);
436 	mutex_unlock(&qspi->lock);
437 
438 	return ret;
439 }
440 
441 static int stm32_qspi_setup(struct spi_device *spi)
442 {
443 	struct spi_controller *ctrl = spi->master;
444 	struct stm32_qspi *qspi = spi_controller_get_devdata(ctrl);
445 	struct stm32_qspi_flash *flash;
446 	u32 presc;
447 
448 	if (ctrl->busy)
449 		return -EBUSY;
450 
451 	if (!spi->max_speed_hz)
452 		return -EINVAL;
453 
454 	presc = DIV_ROUND_UP(qspi->clk_rate, spi->max_speed_hz) - 1;
455 
456 	flash = &qspi->flash[spi->chip_select];
457 	flash->qspi = qspi;
458 	flash->cs = spi->chip_select;
459 	flash->presc = presc;
460 
461 	mutex_lock(&qspi->lock);
462 	qspi->cr_reg = 3 << CR_FTHRES_SHIFT | CR_SSHIFT | CR_EN;
463 	writel_relaxed(qspi->cr_reg, qspi->io_base + QSPI_CR);
464 
465 	/* set dcr fsize to max address */
466 	qspi->dcr_reg = DCR_FSIZE_MASK;
467 	writel_relaxed(qspi->dcr_reg, qspi->io_base + QSPI_DCR);
468 	mutex_unlock(&qspi->lock);
469 
470 	return 0;
471 }
472 
473 static int stm32_qspi_dma_setup(struct stm32_qspi *qspi)
474 {
475 	struct dma_slave_config dma_cfg;
476 	struct device *dev = qspi->dev;
477 	int ret = 0;
478 
479 	memset(&dma_cfg, 0, sizeof(dma_cfg));
480 
481 	dma_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
482 	dma_cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
483 	dma_cfg.src_addr = qspi->phys_base + QSPI_DR;
484 	dma_cfg.dst_addr = qspi->phys_base + QSPI_DR;
485 	dma_cfg.src_maxburst = 4;
486 	dma_cfg.dst_maxburst = 4;
487 
488 	qspi->dma_chrx = dma_request_chan(dev, "rx");
489 	if (IS_ERR(qspi->dma_chrx)) {
490 		ret = PTR_ERR(qspi->dma_chrx);
491 		qspi->dma_chrx = NULL;
492 		if (ret == -EPROBE_DEFER)
493 			goto out;
494 	} else {
495 		if (dmaengine_slave_config(qspi->dma_chrx, &dma_cfg)) {
496 			dev_err(dev, "dma rx config failed\n");
497 			dma_release_channel(qspi->dma_chrx);
498 			qspi->dma_chrx = NULL;
499 		}
500 	}
501 
502 	qspi->dma_chtx = dma_request_chan(dev, "tx");
503 	if (IS_ERR(qspi->dma_chtx)) {
504 		ret = PTR_ERR(qspi->dma_chtx);
505 		qspi->dma_chtx = NULL;
506 	} else {
507 		if (dmaengine_slave_config(qspi->dma_chtx, &dma_cfg)) {
508 			dev_err(dev, "dma tx config failed\n");
509 			dma_release_channel(qspi->dma_chtx);
510 			qspi->dma_chtx = NULL;
511 		}
512 	}
513 
514 out:
515 	init_completion(&qspi->dma_completion);
516 
517 	if (ret != -EPROBE_DEFER)
518 		ret = 0;
519 
520 	return ret;
521 }
522 
523 static void stm32_qspi_dma_free(struct stm32_qspi *qspi)
524 {
525 	if (qspi->dma_chtx)
526 		dma_release_channel(qspi->dma_chtx);
527 	if (qspi->dma_chrx)
528 		dma_release_channel(qspi->dma_chrx);
529 }
530 
531 /*
532  * no special host constraint, so use default spi_mem_default_supports_op
533  * to check supported mode.
534  */
535 static const struct spi_controller_mem_ops stm32_qspi_mem_ops = {
536 	.exec_op = stm32_qspi_exec_op,
537 };
538 
539 static void stm32_qspi_release(struct stm32_qspi *qspi)
540 {
541 	/* disable qspi */
542 	writel_relaxed(0, qspi->io_base + QSPI_CR);
543 	stm32_qspi_dma_free(qspi);
544 	mutex_destroy(&qspi->lock);
545 	clk_disable_unprepare(qspi->clk);
546 }
547 
548 static int stm32_qspi_probe(struct platform_device *pdev)
549 {
550 	struct device *dev = &pdev->dev;
551 	struct spi_controller *ctrl;
552 	struct reset_control *rstc;
553 	struct stm32_qspi *qspi;
554 	struct resource *res;
555 	int ret, irq;
556 
557 	ctrl = spi_alloc_master(dev, sizeof(*qspi));
558 	if (!ctrl)
559 		return -ENOMEM;
560 
561 	qspi = spi_controller_get_devdata(ctrl);
562 	qspi->ctrl = ctrl;
563 
564 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi");
565 	qspi->io_base = devm_ioremap_resource(dev, res);
566 	if (IS_ERR(qspi->io_base)) {
567 		ret = PTR_ERR(qspi->io_base);
568 		goto err_master_put;
569 	}
570 
571 	qspi->phys_base = res->start;
572 
573 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_mm");
574 	qspi->mm_base = devm_ioremap_resource(dev, res);
575 	if (IS_ERR(qspi->mm_base)) {
576 		ret = PTR_ERR(qspi->mm_base);
577 		goto err_master_put;
578 	}
579 
580 	qspi->mm_size = resource_size(res);
581 	if (qspi->mm_size > STM32_QSPI_MAX_MMAP_SZ) {
582 		ret = -EINVAL;
583 		goto err_master_put;
584 	}
585 
586 	irq = platform_get_irq(pdev, 0);
587 	if (irq < 0) {
588 		ret = irq;
589 		goto err_master_put;
590 	}
591 
592 	ret = devm_request_irq(dev, irq, stm32_qspi_irq, 0,
593 			       dev_name(dev), qspi);
594 	if (ret) {
595 		dev_err(dev, "failed to request irq\n");
596 		goto err_master_put;
597 	}
598 
599 	init_completion(&qspi->data_completion);
600 
601 	qspi->clk = devm_clk_get(dev, NULL);
602 	if (IS_ERR(qspi->clk)) {
603 		ret = PTR_ERR(qspi->clk);
604 		goto err_master_put;
605 	}
606 
607 	qspi->clk_rate = clk_get_rate(qspi->clk);
608 	if (!qspi->clk_rate) {
609 		ret = -EINVAL;
610 		goto err_master_put;
611 	}
612 
613 	ret = clk_prepare_enable(qspi->clk);
614 	if (ret) {
615 		dev_err(dev, "can not enable the clock\n");
616 		goto err_master_put;
617 	}
618 
619 	rstc = devm_reset_control_get_exclusive(dev, NULL);
620 	if (IS_ERR(rstc)) {
621 		ret = PTR_ERR(rstc);
622 		if (ret == -EPROBE_DEFER)
623 			goto err_qspi_release;
624 	} else {
625 		reset_control_assert(rstc);
626 		udelay(2);
627 		reset_control_deassert(rstc);
628 	}
629 
630 	qspi->dev = dev;
631 	platform_set_drvdata(pdev, qspi);
632 	ret = stm32_qspi_dma_setup(qspi);
633 	if (ret)
634 		goto err_qspi_release;
635 
636 	mutex_init(&qspi->lock);
637 
638 	ctrl->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD
639 		| SPI_TX_DUAL | SPI_TX_QUAD;
640 	ctrl->setup = stm32_qspi_setup;
641 	ctrl->bus_num = -1;
642 	ctrl->mem_ops = &stm32_qspi_mem_ops;
643 	ctrl->num_chipselect = STM32_QSPI_MAX_NORCHIP;
644 	ctrl->dev.of_node = dev->of_node;
645 
646 	ret = devm_spi_register_master(dev, ctrl);
647 	if (!ret)
648 		return 0;
649 
650 err_qspi_release:
651 	stm32_qspi_release(qspi);
652 err_master_put:
653 	spi_master_put(qspi->ctrl);
654 
655 	return ret;
656 }
657 
658 static int stm32_qspi_remove(struct platform_device *pdev)
659 {
660 	struct stm32_qspi *qspi = platform_get_drvdata(pdev);
661 
662 	stm32_qspi_release(qspi);
663 	return 0;
664 }
665 
666 static int __maybe_unused stm32_qspi_suspend(struct device *dev)
667 {
668 	struct stm32_qspi *qspi = dev_get_drvdata(dev);
669 
670 	clk_disable_unprepare(qspi->clk);
671 	pinctrl_pm_select_sleep_state(dev);
672 
673 	return 0;
674 }
675 
676 static int __maybe_unused stm32_qspi_resume(struct device *dev)
677 {
678 	struct stm32_qspi *qspi = dev_get_drvdata(dev);
679 
680 	pinctrl_pm_select_default_state(dev);
681 	clk_prepare_enable(qspi->clk);
682 
683 	writel_relaxed(qspi->cr_reg, qspi->io_base + QSPI_CR);
684 	writel_relaxed(qspi->dcr_reg, qspi->io_base + QSPI_DCR);
685 
686 	return 0;
687 }
688 
689 static SIMPLE_DEV_PM_OPS(stm32_qspi_pm_ops, stm32_qspi_suspend, stm32_qspi_resume);
690 
691 static const struct of_device_id stm32_qspi_match[] = {
692 	{.compatible = "st,stm32f469-qspi"},
693 	{}
694 };
695 MODULE_DEVICE_TABLE(of, stm32_qspi_match);
696 
697 static struct platform_driver stm32_qspi_driver = {
698 	.probe	= stm32_qspi_probe,
699 	.remove	= stm32_qspi_remove,
700 	.driver	= {
701 		.name = "stm32-qspi",
702 		.of_match_table = stm32_qspi_match,
703 		.pm = &stm32_qspi_pm_ops,
704 	},
705 };
706 module_platform_driver(stm32_qspi_driver);
707 
708 MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
709 MODULE_DESCRIPTION("STMicroelectronics STM32 quad spi driver");
710 MODULE_LICENSE("GPL v2");
711