xref: /linux/drivers/spi/spi-stm32-qspi.c (revision b77e0ce62d63a761ffb7f7245a215a49f5921c2f)
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/pm_runtime.h>
20 #include <linux/platform_device.h>
21 #include <linux/reset.h>
22 #include <linux/sizes.h>
23 #include <linux/spi/spi-mem.h>
24 
25 #define QSPI_CR			0x00
26 #define CR_EN			BIT(0)
27 #define CR_ABORT		BIT(1)
28 #define CR_DMAEN		BIT(2)
29 #define CR_TCEN			BIT(3)
30 #define CR_SSHIFT		BIT(4)
31 #define CR_DFM			BIT(6)
32 #define CR_FSEL			BIT(7)
33 #define CR_FTHRES_SHIFT		8
34 #define CR_TEIE			BIT(16)
35 #define CR_TCIE			BIT(17)
36 #define CR_FTIE			BIT(18)
37 #define CR_SMIE			BIT(19)
38 #define CR_TOIE			BIT(20)
39 #define CR_PRESC_MASK		GENMASK(31, 24)
40 
41 #define QSPI_DCR		0x04
42 #define DCR_FSIZE_MASK		GENMASK(20, 16)
43 
44 #define QSPI_SR			0x08
45 #define SR_TEF			BIT(0)
46 #define SR_TCF			BIT(1)
47 #define SR_FTF			BIT(2)
48 #define SR_SMF			BIT(3)
49 #define SR_TOF			BIT(4)
50 #define SR_BUSY			BIT(5)
51 #define SR_FLEVEL_MASK		GENMASK(13, 8)
52 
53 #define QSPI_FCR		0x0c
54 #define FCR_CTEF		BIT(0)
55 #define FCR_CTCF		BIT(1)
56 
57 #define QSPI_DLR		0x10
58 
59 #define QSPI_CCR		0x14
60 #define CCR_INST_MASK		GENMASK(7, 0)
61 #define CCR_IMODE_MASK		GENMASK(9, 8)
62 #define CCR_ADMODE_MASK		GENMASK(11, 10)
63 #define CCR_ADSIZE_MASK		GENMASK(13, 12)
64 #define CCR_DCYC_MASK		GENMASK(22, 18)
65 #define CCR_DMODE_MASK		GENMASK(25, 24)
66 #define CCR_FMODE_MASK		GENMASK(27, 26)
67 #define CCR_FMODE_INDW		(0U << 26)
68 #define CCR_FMODE_INDR		(1U << 26)
69 #define CCR_FMODE_APM		(2U << 26)
70 #define CCR_FMODE_MM		(3U << 26)
71 #define CCR_BUSWIDTH_0		0x0
72 #define CCR_BUSWIDTH_1		0x1
73 #define CCR_BUSWIDTH_2		0x2
74 #define CCR_BUSWIDTH_4		0x3
75 
76 #define QSPI_AR			0x18
77 #define QSPI_ABR		0x1c
78 #define QSPI_DR			0x20
79 #define QSPI_PSMKR		0x24
80 #define QSPI_PSMAR		0x28
81 #define QSPI_PIR		0x2c
82 #define QSPI_LPTR		0x30
83 
84 #define STM32_QSPI_MAX_MMAP_SZ	SZ_256M
85 #define STM32_QSPI_MAX_NORCHIP	2
86 
87 #define STM32_FIFO_TIMEOUT_US 30000
88 #define STM32_BUSY_TIMEOUT_US 100000
89 #define STM32_ABT_TIMEOUT_US 100000
90 #define STM32_COMP_TIMEOUT_MS 1000
91 #define STM32_AUTOSUSPEND_DELAY -1
92 
93 struct stm32_qspi_flash {
94 	struct stm32_qspi *qspi;
95 	u32 cs;
96 	u32 presc;
97 };
98 
99 struct stm32_qspi {
100 	struct device *dev;
101 	struct spi_controller *ctrl;
102 	phys_addr_t phys_base;
103 	void __iomem *io_base;
104 	void __iomem *mm_base;
105 	resource_size_t mm_size;
106 	struct clk *clk;
107 	u32 clk_rate;
108 	struct stm32_qspi_flash flash[STM32_QSPI_MAX_NORCHIP];
109 	struct completion data_completion;
110 	u32 fmode;
111 
112 	struct dma_chan *dma_chtx;
113 	struct dma_chan *dma_chrx;
114 	struct completion dma_completion;
115 
116 	u32 cr_reg;
117 	u32 dcr_reg;
118 
119 	/*
120 	 * to protect device configuration, could be different between
121 	 * 2 flash access (bk1, bk2)
122 	 */
123 	struct mutex lock;
124 };
125 
126 static irqreturn_t stm32_qspi_irq(int irq, void *dev_id)
127 {
128 	struct stm32_qspi *qspi = (struct stm32_qspi *)dev_id;
129 	u32 cr, sr;
130 
131 	sr = readl_relaxed(qspi->io_base + QSPI_SR);
132 
133 	if (sr & (SR_TEF | SR_TCF)) {
134 		/* disable irq */
135 		cr = readl_relaxed(qspi->io_base + QSPI_CR);
136 		cr &= ~CR_TCIE & ~CR_TEIE;
137 		writel_relaxed(cr, qspi->io_base + QSPI_CR);
138 		complete(&qspi->data_completion);
139 	}
140 
141 	return IRQ_HANDLED;
142 }
143 
144 static void stm32_qspi_read_fifo(u8 *val, void __iomem *addr)
145 {
146 	*val = readb_relaxed(addr);
147 }
148 
149 static void stm32_qspi_write_fifo(u8 *val, void __iomem *addr)
150 {
151 	writeb_relaxed(*val, addr);
152 }
153 
154 static int stm32_qspi_tx_poll(struct stm32_qspi *qspi,
155 			      const struct spi_mem_op *op)
156 {
157 	void (*tx_fifo)(u8 *val, void __iomem *addr);
158 	u32 len = op->data.nbytes, sr;
159 	u8 *buf;
160 	int ret;
161 
162 	if (op->data.dir == SPI_MEM_DATA_IN) {
163 		tx_fifo = stm32_qspi_read_fifo;
164 		buf = op->data.buf.in;
165 
166 	} else {
167 		tx_fifo = stm32_qspi_write_fifo;
168 		buf = (u8 *)op->data.buf.out;
169 	}
170 
171 	while (len--) {
172 		ret = readl_relaxed_poll_timeout_atomic(qspi->io_base + QSPI_SR,
173 							sr, (sr & SR_FTF), 1,
174 							STM32_FIFO_TIMEOUT_US);
175 		if (ret) {
176 			dev_err(qspi->dev, "fifo timeout (len:%d stat:%#x)\n",
177 				len, sr);
178 			return ret;
179 		}
180 		tx_fifo(buf++, qspi->io_base + QSPI_DR);
181 	}
182 
183 	return 0;
184 }
185 
186 static int stm32_qspi_tx_mm(struct stm32_qspi *qspi,
187 			    const struct spi_mem_op *op)
188 {
189 	memcpy_fromio(op->data.buf.in, qspi->mm_base + op->addr.val,
190 		      op->data.nbytes);
191 	return 0;
192 }
193 
194 static void stm32_qspi_dma_callback(void *arg)
195 {
196 	struct completion *dma_completion = arg;
197 
198 	complete(dma_completion);
199 }
200 
201 static int stm32_qspi_tx_dma(struct stm32_qspi *qspi,
202 			     const struct spi_mem_op *op)
203 {
204 	struct dma_async_tx_descriptor *desc;
205 	enum dma_transfer_direction dma_dir;
206 	struct dma_chan *dma_ch;
207 	struct sg_table sgt;
208 	dma_cookie_t cookie;
209 	u32 cr, t_out;
210 	int err;
211 
212 	if (op->data.dir == SPI_MEM_DATA_IN) {
213 		dma_dir = DMA_DEV_TO_MEM;
214 		dma_ch = qspi->dma_chrx;
215 	} else {
216 		dma_dir = DMA_MEM_TO_DEV;
217 		dma_ch = qspi->dma_chtx;
218 	}
219 
220 	/*
221 	 * spi_map_buf return -EINVAL if the buffer is not DMA-able
222 	 * (DMA-able: in vmalloc | kmap | virt_addr_valid)
223 	 */
224 	err = spi_controller_dma_map_mem_op_data(qspi->ctrl, op, &sgt);
225 	if (err)
226 		return err;
227 
228 	desc = dmaengine_prep_slave_sg(dma_ch, sgt.sgl, sgt.nents,
229 				       dma_dir, DMA_PREP_INTERRUPT);
230 	if (!desc) {
231 		err = -ENOMEM;
232 		goto out_unmap;
233 	}
234 
235 	cr = readl_relaxed(qspi->io_base + QSPI_CR);
236 
237 	reinit_completion(&qspi->dma_completion);
238 	desc->callback = stm32_qspi_dma_callback;
239 	desc->callback_param = &qspi->dma_completion;
240 	cookie = dmaengine_submit(desc);
241 	err = dma_submit_error(cookie);
242 	if (err)
243 		goto out;
244 
245 	dma_async_issue_pending(dma_ch);
246 
247 	writel_relaxed(cr | CR_DMAEN, qspi->io_base + QSPI_CR);
248 
249 	t_out = sgt.nents * STM32_COMP_TIMEOUT_MS;
250 	if (!wait_for_completion_timeout(&qspi->dma_completion,
251 					 msecs_to_jiffies(t_out)))
252 		err = -ETIMEDOUT;
253 
254 	if (err)
255 		dmaengine_terminate_all(dma_ch);
256 
257 out:
258 	writel_relaxed(cr & ~CR_DMAEN, qspi->io_base + QSPI_CR);
259 out_unmap:
260 	spi_controller_dma_unmap_mem_op_data(qspi->ctrl, op, &sgt);
261 
262 	return err;
263 }
264 
265 static int stm32_qspi_tx(struct stm32_qspi *qspi, const struct spi_mem_op *op)
266 {
267 	if (!op->data.nbytes)
268 		return 0;
269 
270 	if (qspi->fmode == CCR_FMODE_MM)
271 		return stm32_qspi_tx_mm(qspi, op);
272 	else if ((op->data.dir == SPI_MEM_DATA_IN && qspi->dma_chrx) ||
273 		 (op->data.dir == SPI_MEM_DATA_OUT && qspi->dma_chtx))
274 		if (!stm32_qspi_tx_dma(qspi, op))
275 			return 0;
276 
277 	return stm32_qspi_tx_poll(qspi, op);
278 }
279 
280 static int stm32_qspi_wait_nobusy(struct stm32_qspi *qspi)
281 {
282 	u32 sr;
283 
284 	return readl_relaxed_poll_timeout_atomic(qspi->io_base + QSPI_SR, sr,
285 						 !(sr & SR_BUSY), 1,
286 						 STM32_BUSY_TIMEOUT_US);
287 }
288 
289 static int stm32_qspi_wait_cmd(struct stm32_qspi *qspi,
290 			       const struct spi_mem_op *op)
291 {
292 	u32 cr, sr;
293 	int err = 0;
294 
295 	if (!op->data.nbytes)
296 		return stm32_qspi_wait_nobusy(qspi);
297 
298 	if (readl_relaxed(qspi->io_base + QSPI_SR) & SR_TCF)
299 		goto out;
300 
301 	reinit_completion(&qspi->data_completion);
302 	cr = readl_relaxed(qspi->io_base + QSPI_CR);
303 	writel_relaxed(cr | CR_TCIE | CR_TEIE, qspi->io_base + QSPI_CR);
304 
305 	if (!wait_for_completion_timeout(&qspi->data_completion,
306 				msecs_to_jiffies(STM32_COMP_TIMEOUT_MS))) {
307 		err = -ETIMEDOUT;
308 	} else {
309 		sr = readl_relaxed(qspi->io_base + QSPI_SR);
310 		if (sr & SR_TEF)
311 			err = -EIO;
312 	}
313 
314 out:
315 	/* clear flags */
316 	writel_relaxed(FCR_CTCF | FCR_CTEF, qspi->io_base + QSPI_FCR);
317 
318 	return err;
319 }
320 
321 static int stm32_qspi_get_mode(struct stm32_qspi *qspi, u8 buswidth)
322 {
323 	if (buswidth == 4)
324 		return CCR_BUSWIDTH_4;
325 
326 	return buswidth;
327 }
328 
329 static int stm32_qspi_send(struct spi_mem *mem, const struct spi_mem_op *op)
330 {
331 	struct stm32_qspi *qspi = spi_controller_get_devdata(mem->spi->master);
332 	struct stm32_qspi_flash *flash = &qspi->flash[mem->spi->chip_select];
333 	u32 ccr, cr, addr_max;
334 	int timeout, err = 0;
335 
336 	dev_dbg(qspi->dev, "cmd:%#x mode:%d.%d.%d.%d addr:%#llx len:%#x\n",
337 		op->cmd.opcode, op->cmd.buswidth, op->addr.buswidth,
338 		op->dummy.buswidth, op->data.buswidth,
339 		op->addr.val, op->data.nbytes);
340 
341 	err = stm32_qspi_wait_nobusy(qspi);
342 	if (err)
343 		goto abort;
344 
345 	addr_max = op->addr.val + op->data.nbytes + 1;
346 
347 	if (op->data.dir == SPI_MEM_DATA_IN) {
348 		if (addr_max < qspi->mm_size &&
349 		    op->addr.buswidth)
350 			qspi->fmode = CCR_FMODE_MM;
351 		else
352 			qspi->fmode = CCR_FMODE_INDR;
353 	} else {
354 		qspi->fmode = CCR_FMODE_INDW;
355 	}
356 
357 	cr = readl_relaxed(qspi->io_base + QSPI_CR);
358 	cr &= ~CR_PRESC_MASK & ~CR_FSEL;
359 	cr |= FIELD_PREP(CR_PRESC_MASK, flash->presc);
360 	cr |= FIELD_PREP(CR_FSEL, flash->cs);
361 	writel_relaxed(cr, qspi->io_base + QSPI_CR);
362 
363 	if (op->data.nbytes)
364 		writel_relaxed(op->data.nbytes - 1,
365 			       qspi->io_base + QSPI_DLR);
366 	else
367 		qspi->fmode = CCR_FMODE_INDW;
368 
369 	ccr = qspi->fmode;
370 	ccr |= FIELD_PREP(CCR_INST_MASK, op->cmd.opcode);
371 	ccr |= FIELD_PREP(CCR_IMODE_MASK,
372 			  stm32_qspi_get_mode(qspi, op->cmd.buswidth));
373 
374 	if (op->addr.nbytes) {
375 		ccr |= FIELD_PREP(CCR_ADMODE_MASK,
376 				  stm32_qspi_get_mode(qspi, op->addr.buswidth));
377 		ccr |= FIELD_PREP(CCR_ADSIZE_MASK, op->addr.nbytes - 1);
378 	}
379 
380 	if (op->dummy.buswidth && op->dummy.nbytes)
381 		ccr |= FIELD_PREP(CCR_DCYC_MASK,
382 				  op->dummy.nbytes * 8 / op->dummy.buswidth);
383 
384 	if (op->data.nbytes) {
385 		ccr |= FIELD_PREP(CCR_DMODE_MASK,
386 				  stm32_qspi_get_mode(qspi, op->data.buswidth));
387 	}
388 
389 	writel_relaxed(ccr, qspi->io_base + QSPI_CCR);
390 
391 	if (op->addr.nbytes && qspi->fmode != CCR_FMODE_MM)
392 		writel_relaxed(op->addr.val, qspi->io_base + QSPI_AR);
393 
394 	err = stm32_qspi_tx(qspi, op);
395 
396 	/*
397 	 * Abort in:
398 	 * -error case
399 	 * -read memory map: prefetching must be stopped if we read the last
400 	 *  byte of device (device size - fifo size). like device size is not
401 	 *  knows, the prefetching is always stop.
402 	 */
403 	if (err || qspi->fmode == CCR_FMODE_MM)
404 		goto abort;
405 
406 	/* wait end of tx in indirect mode */
407 	err = stm32_qspi_wait_cmd(qspi, op);
408 	if (err)
409 		goto abort;
410 
411 	return 0;
412 
413 abort:
414 	cr = readl_relaxed(qspi->io_base + QSPI_CR) | CR_ABORT;
415 	writel_relaxed(cr, qspi->io_base + QSPI_CR);
416 
417 	/* wait clear of abort bit by hw */
418 	timeout = readl_relaxed_poll_timeout_atomic(qspi->io_base + QSPI_CR,
419 						    cr, !(cr & CR_ABORT), 1,
420 						    STM32_ABT_TIMEOUT_US);
421 
422 	writel_relaxed(FCR_CTCF, qspi->io_base + QSPI_FCR);
423 
424 	if (err || timeout)
425 		dev_err(qspi->dev, "%s err:%d abort timeout:%d\n",
426 			__func__, err, timeout);
427 
428 	return err;
429 }
430 
431 static int stm32_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
432 {
433 	struct stm32_qspi *qspi = spi_controller_get_devdata(mem->spi->master);
434 	int ret;
435 
436 	ret = pm_runtime_get_sync(qspi->dev);
437 	if (ret < 0) {
438 		pm_runtime_put_noidle(qspi->dev);
439 		return ret;
440 	}
441 
442 	mutex_lock(&qspi->lock);
443 	ret = stm32_qspi_send(mem, op);
444 	mutex_unlock(&qspi->lock);
445 
446 	pm_runtime_mark_last_busy(qspi->dev);
447 	pm_runtime_put_autosuspend(qspi->dev);
448 
449 	return ret;
450 }
451 
452 static int stm32_qspi_setup(struct spi_device *spi)
453 {
454 	struct spi_controller *ctrl = spi->master;
455 	struct stm32_qspi *qspi = spi_controller_get_devdata(ctrl);
456 	struct stm32_qspi_flash *flash;
457 	u32 presc;
458 	int ret;
459 
460 	if (ctrl->busy)
461 		return -EBUSY;
462 
463 	if (!spi->max_speed_hz)
464 		return -EINVAL;
465 
466 	ret = pm_runtime_get_sync(qspi->dev);
467 	if (ret < 0) {
468 		pm_runtime_put_noidle(qspi->dev);
469 		return ret;
470 	}
471 
472 	presc = DIV_ROUND_UP(qspi->clk_rate, spi->max_speed_hz) - 1;
473 
474 	flash = &qspi->flash[spi->chip_select];
475 	flash->qspi = qspi;
476 	flash->cs = spi->chip_select;
477 	flash->presc = presc;
478 
479 	mutex_lock(&qspi->lock);
480 	qspi->cr_reg = 3 << CR_FTHRES_SHIFT | CR_SSHIFT | CR_EN;
481 	writel_relaxed(qspi->cr_reg, qspi->io_base + QSPI_CR);
482 
483 	/* set dcr fsize to max address */
484 	qspi->dcr_reg = DCR_FSIZE_MASK;
485 	writel_relaxed(qspi->dcr_reg, qspi->io_base + QSPI_DCR);
486 	mutex_unlock(&qspi->lock);
487 
488 	pm_runtime_mark_last_busy(qspi->dev);
489 	pm_runtime_put_autosuspend(qspi->dev);
490 
491 	return 0;
492 }
493 
494 static int stm32_qspi_dma_setup(struct stm32_qspi *qspi)
495 {
496 	struct dma_slave_config dma_cfg;
497 	struct device *dev = qspi->dev;
498 	int ret = 0;
499 
500 	memset(&dma_cfg, 0, sizeof(dma_cfg));
501 
502 	dma_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
503 	dma_cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
504 	dma_cfg.src_addr = qspi->phys_base + QSPI_DR;
505 	dma_cfg.dst_addr = qspi->phys_base + QSPI_DR;
506 	dma_cfg.src_maxburst = 4;
507 	dma_cfg.dst_maxburst = 4;
508 
509 	qspi->dma_chrx = dma_request_chan(dev, "rx");
510 	if (IS_ERR(qspi->dma_chrx)) {
511 		ret = PTR_ERR(qspi->dma_chrx);
512 		qspi->dma_chrx = NULL;
513 		if (ret == -EPROBE_DEFER)
514 			goto out;
515 	} else {
516 		if (dmaengine_slave_config(qspi->dma_chrx, &dma_cfg)) {
517 			dev_err(dev, "dma rx config failed\n");
518 			dma_release_channel(qspi->dma_chrx);
519 			qspi->dma_chrx = NULL;
520 		}
521 	}
522 
523 	qspi->dma_chtx = dma_request_chan(dev, "tx");
524 	if (IS_ERR(qspi->dma_chtx)) {
525 		ret = PTR_ERR(qspi->dma_chtx);
526 		qspi->dma_chtx = NULL;
527 	} else {
528 		if (dmaengine_slave_config(qspi->dma_chtx, &dma_cfg)) {
529 			dev_err(dev, "dma tx config failed\n");
530 			dma_release_channel(qspi->dma_chtx);
531 			qspi->dma_chtx = NULL;
532 		}
533 	}
534 
535 out:
536 	init_completion(&qspi->dma_completion);
537 
538 	if (ret != -EPROBE_DEFER)
539 		ret = 0;
540 
541 	return ret;
542 }
543 
544 static void stm32_qspi_dma_free(struct stm32_qspi *qspi)
545 {
546 	if (qspi->dma_chtx)
547 		dma_release_channel(qspi->dma_chtx);
548 	if (qspi->dma_chrx)
549 		dma_release_channel(qspi->dma_chrx);
550 }
551 
552 /*
553  * no special host constraint, so use default spi_mem_default_supports_op
554  * to check supported mode.
555  */
556 static const struct spi_controller_mem_ops stm32_qspi_mem_ops = {
557 	.exec_op = stm32_qspi_exec_op,
558 };
559 
560 static int stm32_qspi_probe(struct platform_device *pdev)
561 {
562 	struct device *dev = &pdev->dev;
563 	struct spi_controller *ctrl;
564 	struct reset_control *rstc;
565 	struct stm32_qspi *qspi;
566 	struct resource *res;
567 	int ret, irq;
568 
569 	ctrl = spi_alloc_master(dev, sizeof(*qspi));
570 	if (!ctrl)
571 		return -ENOMEM;
572 
573 	qspi = spi_controller_get_devdata(ctrl);
574 	qspi->ctrl = ctrl;
575 
576 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi");
577 	qspi->io_base = devm_ioremap_resource(dev, res);
578 	if (IS_ERR(qspi->io_base)) {
579 		ret = PTR_ERR(qspi->io_base);
580 		goto err_master_put;
581 	}
582 
583 	qspi->phys_base = res->start;
584 
585 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_mm");
586 	qspi->mm_base = devm_ioremap_resource(dev, res);
587 	if (IS_ERR(qspi->mm_base)) {
588 		ret = PTR_ERR(qspi->mm_base);
589 		goto err_master_put;
590 	}
591 
592 	qspi->mm_size = resource_size(res);
593 	if (qspi->mm_size > STM32_QSPI_MAX_MMAP_SZ) {
594 		ret = -EINVAL;
595 		goto err_master_put;
596 	}
597 
598 	irq = platform_get_irq(pdev, 0);
599 	if (irq < 0) {
600 		ret = irq;
601 		goto err_master_put;
602 	}
603 
604 	ret = devm_request_irq(dev, irq, stm32_qspi_irq, 0,
605 			       dev_name(dev), qspi);
606 	if (ret) {
607 		dev_err(dev, "failed to request irq\n");
608 		goto err_master_put;
609 	}
610 
611 	init_completion(&qspi->data_completion);
612 
613 	qspi->clk = devm_clk_get(dev, NULL);
614 	if (IS_ERR(qspi->clk)) {
615 		ret = PTR_ERR(qspi->clk);
616 		goto err_master_put;
617 	}
618 
619 	qspi->clk_rate = clk_get_rate(qspi->clk);
620 	if (!qspi->clk_rate) {
621 		ret = -EINVAL;
622 		goto err_master_put;
623 	}
624 
625 	ret = clk_prepare_enable(qspi->clk);
626 	if (ret) {
627 		dev_err(dev, "can not enable the clock\n");
628 		goto err_master_put;
629 	}
630 
631 	rstc = devm_reset_control_get_exclusive(dev, NULL);
632 	if (IS_ERR(rstc)) {
633 		ret = PTR_ERR(rstc);
634 		if (ret == -EPROBE_DEFER)
635 			goto err_clk_disable;
636 	} else {
637 		reset_control_assert(rstc);
638 		udelay(2);
639 		reset_control_deassert(rstc);
640 	}
641 
642 	qspi->dev = dev;
643 	platform_set_drvdata(pdev, qspi);
644 	ret = stm32_qspi_dma_setup(qspi);
645 	if (ret)
646 		goto err_dma_free;
647 
648 	mutex_init(&qspi->lock);
649 
650 	ctrl->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD
651 		| SPI_TX_DUAL | SPI_TX_QUAD;
652 	ctrl->setup = stm32_qspi_setup;
653 	ctrl->bus_num = -1;
654 	ctrl->mem_ops = &stm32_qspi_mem_ops;
655 	ctrl->num_chipselect = STM32_QSPI_MAX_NORCHIP;
656 	ctrl->dev.of_node = dev->of_node;
657 
658 	pm_runtime_set_autosuspend_delay(dev, STM32_AUTOSUSPEND_DELAY);
659 	pm_runtime_use_autosuspend(dev);
660 	pm_runtime_set_active(dev);
661 	pm_runtime_enable(dev);
662 	pm_runtime_get_noresume(dev);
663 
664 	ret = devm_spi_register_master(dev, ctrl);
665 	if (ret)
666 		goto err_pm_runtime_free;
667 
668 	pm_runtime_mark_last_busy(dev);
669 	pm_runtime_put_autosuspend(dev);
670 
671 	return 0;
672 
673 err_pm_runtime_free:
674 	pm_runtime_get_sync(qspi->dev);
675 	/* disable qspi */
676 	writel_relaxed(0, qspi->io_base + QSPI_CR);
677 	mutex_destroy(&qspi->lock);
678 	pm_runtime_put_noidle(qspi->dev);
679 	pm_runtime_disable(qspi->dev);
680 	pm_runtime_set_suspended(qspi->dev);
681 	pm_runtime_dont_use_autosuspend(qspi->dev);
682 err_dma_free:
683 	stm32_qspi_dma_free(qspi);
684 err_clk_disable:
685 	clk_disable_unprepare(qspi->clk);
686 err_master_put:
687 	spi_master_put(qspi->ctrl);
688 
689 	return ret;
690 }
691 
692 static int stm32_qspi_remove(struct platform_device *pdev)
693 {
694 	struct stm32_qspi *qspi = platform_get_drvdata(pdev);
695 
696 	pm_runtime_get_sync(qspi->dev);
697 	/* disable qspi */
698 	writel_relaxed(0, qspi->io_base + QSPI_CR);
699 	stm32_qspi_dma_free(qspi);
700 	mutex_destroy(&qspi->lock);
701 	pm_runtime_put_noidle(qspi->dev);
702 	pm_runtime_disable(qspi->dev);
703 	pm_runtime_set_suspended(qspi->dev);
704 	pm_runtime_dont_use_autosuspend(qspi->dev);
705 	clk_disable_unprepare(qspi->clk);
706 
707 	return 0;
708 }
709 
710 static int __maybe_unused stm32_qspi_runtime_suspend(struct device *dev)
711 {
712 	struct stm32_qspi *qspi = dev_get_drvdata(dev);
713 
714 	clk_disable_unprepare(qspi->clk);
715 
716 	return 0;
717 }
718 
719 static int __maybe_unused stm32_qspi_runtime_resume(struct device *dev)
720 {
721 	struct stm32_qspi *qspi = dev_get_drvdata(dev);
722 
723 	return clk_prepare_enable(qspi->clk);
724 }
725 
726 static int __maybe_unused stm32_qspi_suspend(struct device *dev)
727 {
728 	pinctrl_pm_select_sleep_state(dev);
729 
730 	return 0;
731 }
732 
733 static int __maybe_unused stm32_qspi_resume(struct device *dev)
734 {
735 	struct stm32_qspi *qspi = dev_get_drvdata(dev);
736 
737 	pinctrl_pm_select_default_state(dev);
738 	clk_prepare_enable(qspi->clk);
739 
740 	writel_relaxed(qspi->cr_reg, qspi->io_base + QSPI_CR);
741 	writel_relaxed(qspi->dcr_reg, qspi->io_base + QSPI_DCR);
742 
743 	pm_runtime_mark_last_busy(qspi->dev);
744 	pm_runtime_put_autosuspend(qspi->dev);
745 
746 	return 0;
747 }
748 
749 static const struct dev_pm_ops stm32_qspi_pm_ops = {
750 	SET_RUNTIME_PM_OPS(stm32_qspi_runtime_suspend,
751 			   stm32_qspi_runtime_resume, NULL)
752 	SET_SYSTEM_SLEEP_PM_OPS(stm32_qspi_suspend, stm32_qspi_resume)
753 };
754 
755 static const struct of_device_id stm32_qspi_match[] = {
756 	{.compatible = "st,stm32f469-qspi"},
757 	{}
758 };
759 MODULE_DEVICE_TABLE(of, stm32_qspi_match);
760 
761 static struct platform_driver stm32_qspi_driver = {
762 	.probe	= stm32_qspi_probe,
763 	.remove	= stm32_qspi_remove,
764 	.driver	= {
765 		.name = "stm32-qspi",
766 		.of_match_table = stm32_qspi_match,
767 		.pm = &stm32_qspi_pm_ops,
768 	},
769 };
770 module_platform_driver(stm32_qspi_driver);
771 
772 MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
773 MODULE_DESCRIPTION("STMicroelectronics STM32 quad spi driver");
774 MODULE_LICENSE("GPL v2");
775