xref: /openbmc/linux/drivers/spi/spi-mxs.c (revision 0e17c50f)
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Freescale MXS SPI master driver
4 //
5 // Copyright 2012 DENX Software Engineering, GmbH.
6 // Copyright 2012 Freescale Semiconductor, Inc.
7 // Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
8 //
9 // Rework and transition to new API by:
10 // Marek Vasut <marex@denx.de>
11 //
12 // Based on previous attempt by:
13 // Fabio Estevam <fabio.estevam@freescale.com>
14 //
15 // Based on code from U-Boot bootloader by:
16 // Marek Vasut <marex@denx.de>
17 //
18 // Based on spi-stmp.c, which is:
19 // Author: Dmitry Pervushin <dimka@embeddedalley.com>
20 
21 #include <linux/kernel.h>
22 #include <linux/ioport.h>
23 #include <linux/of.h>
24 #include <linux/of_device.h>
25 #include <linux/of_gpio.h>
26 #include <linux/platform_device.h>
27 #include <linux/delay.h>
28 #include <linux/interrupt.h>
29 #include <linux/dma-mapping.h>
30 #include <linux/dmaengine.h>
31 #include <linux/highmem.h>
32 #include <linux/clk.h>
33 #include <linux/err.h>
34 #include <linux/completion.h>
35 #include <linux/gpio.h>
36 #include <linux/regulator/consumer.h>
37 #include <linux/pm_runtime.h>
38 #include <linux/module.h>
39 #include <linux/stmp_device.h>
40 #include <linux/spi/spi.h>
41 #include <linux/spi/mxs-spi.h>
42 #include <trace/events/spi.h>
43 
44 #define DRIVER_NAME		"mxs-spi"
45 
46 /* Use 10S timeout for very long transfers, it should suffice. */
47 #define SSP_TIMEOUT		10000
48 
49 #define SG_MAXLEN		0xff00
50 
51 /*
52  * Flags for txrx functions.  More efficient that using an argument register for
53  * each one.
54  */
55 #define TXRX_WRITE		(1<<0)	/* This is a write */
56 #define TXRX_DEASSERT_CS	(1<<1)	/* De-assert CS at end of txrx */
57 
58 struct mxs_spi {
59 	struct mxs_ssp		ssp;
60 	struct completion	c;
61 	unsigned int		sck;	/* Rate requested (vs actual) */
62 };
63 
64 static int mxs_spi_setup_transfer(struct spi_device *dev,
65 				  const struct spi_transfer *t)
66 {
67 	struct mxs_spi *spi = spi_master_get_devdata(dev->master);
68 	struct mxs_ssp *ssp = &spi->ssp;
69 	const unsigned int hz = min(dev->max_speed_hz, t->speed_hz);
70 
71 	if (hz == 0) {
72 		dev_err(&dev->dev, "SPI clock rate of zero not allowed\n");
73 		return -EINVAL;
74 	}
75 
76 	if (hz != spi->sck) {
77 		mxs_ssp_set_clk_rate(ssp, hz);
78 		/*
79 		 * Save requested rate, hz, rather than the actual rate,
80 		 * ssp->clk_rate.  Otherwise we would set the rate every transfer
81 		 * when the actual rate is not quite the same as requested rate.
82 		 */
83 		spi->sck = hz;
84 		/*
85 		 * Perhaps we should return an error if the actual clock is
86 		 * nowhere close to what was requested?
87 		 */
88 	}
89 
90 	writel(BM_SSP_CTRL0_LOCK_CS,
91 		ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
92 
93 	writel(BF_SSP_CTRL1_SSP_MODE(BV_SSP_CTRL1_SSP_MODE__SPI) |
94 	       BF_SSP_CTRL1_WORD_LENGTH(BV_SSP_CTRL1_WORD_LENGTH__EIGHT_BITS) |
95 	       ((dev->mode & SPI_CPOL) ? BM_SSP_CTRL1_POLARITY : 0) |
96 	       ((dev->mode & SPI_CPHA) ? BM_SSP_CTRL1_PHASE : 0),
97 	       ssp->base + HW_SSP_CTRL1(ssp));
98 
99 	writel(0x0, ssp->base + HW_SSP_CMD0);
100 	writel(0x0, ssp->base + HW_SSP_CMD1);
101 
102 	return 0;
103 }
104 
105 static u32 mxs_spi_cs_to_reg(unsigned cs)
106 {
107 	u32 select = 0;
108 
109 	/*
110 	 * i.MX28 Datasheet: 17.10.1: HW_SSP_CTRL0
111 	 *
112 	 * The bits BM_SSP_CTRL0_WAIT_FOR_CMD and BM_SSP_CTRL0_WAIT_FOR_IRQ
113 	 * in HW_SSP_CTRL0 register do have multiple usage, please refer to
114 	 * the datasheet for further details. In SPI mode, they are used to
115 	 * toggle the chip-select lines (nCS pins).
116 	 */
117 	if (cs & 1)
118 		select |= BM_SSP_CTRL0_WAIT_FOR_CMD;
119 	if (cs & 2)
120 		select |= BM_SSP_CTRL0_WAIT_FOR_IRQ;
121 
122 	return select;
123 }
124 
125 static int mxs_ssp_wait(struct mxs_spi *spi, int offset, int mask, bool set)
126 {
127 	const unsigned long timeout = jiffies + msecs_to_jiffies(SSP_TIMEOUT);
128 	struct mxs_ssp *ssp = &spi->ssp;
129 	u32 reg;
130 
131 	do {
132 		reg = readl_relaxed(ssp->base + offset);
133 
134 		if (!set)
135 			reg = ~reg;
136 
137 		reg &= mask;
138 
139 		if (reg == mask)
140 			return 0;
141 	} while (time_before(jiffies, timeout));
142 
143 	return -ETIMEDOUT;
144 }
145 
146 static void mxs_ssp_dma_irq_callback(void *param)
147 {
148 	struct mxs_spi *spi = param;
149 
150 	complete(&spi->c);
151 }
152 
153 static irqreturn_t mxs_ssp_irq_handler(int irq, void *dev_id)
154 {
155 	struct mxs_ssp *ssp = dev_id;
156 
157 	dev_err(ssp->dev, "%s[%i] CTRL1=%08x STATUS=%08x\n",
158 		__func__, __LINE__,
159 		readl(ssp->base + HW_SSP_CTRL1(ssp)),
160 		readl(ssp->base + HW_SSP_STATUS(ssp)));
161 	return IRQ_HANDLED;
162 }
163 
164 static int mxs_spi_txrx_dma(struct mxs_spi *spi,
165 			    unsigned char *buf, int len,
166 			    unsigned int flags)
167 {
168 	struct mxs_ssp *ssp = &spi->ssp;
169 	struct dma_async_tx_descriptor *desc = NULL;
170 	const bool vmalloced_buf = is_vmalloc_addr(buf);
171 	const int desc_len = vmalloced_buf ? PAGE_SIZE : SG_MAXLEN;
172 	const int sgs = DIV_ROUND_UP(len, desc_len);
173 	int sg_count;
174 	int min, ret;
175 	u32 ctrl0;
176 	struct page *vm_page;
177 	struct {
178 		u32			pio[4];
179 		struct scatterlist	sg;
180 	} *dma_xfer;
181 
182 	if (!len)
183 		return -EINVAL;
184 
185 	dma_xfer = kcalloc(sgs, sizeof(*dma_xfer), GFP_KERNEL);
186 	if (!dma_xfer)
187 		return -ENOMEM;
188 
189 	reinit_completion(&spi->c);
190 
191 	/* Chip select was already programmed into CTRL0 */
192 	ctrl0 = readl(ssp->base + HW_SSP_CTRL0);
193 	ctrl0 &= ~(BM_SSP_CTRL0_XFER_COUNT | BM_SSP_CTRL0_IGNORE_CRC |
194 		 BM_SSP_CTRL0_READ);
195 	ctrl0 |= BM_SSP_CTRL0_DATA_XFER;
196 
197 	if (!(flags & TXRX_WRITE))
198 		ctrl0 |= BM_SSP_CTRL0_READ;
199 
200 	/* Queue the DMA data transfer. */
201 	for (sg_count = 0; sg_count < sgs; sg_count++) {
202 		/* Prepare the transfer descriptor. */
203 		min = min(len, desc_len);
204 
205 		/*
206 		 * De-assert CS on last segment if flag is set (i.e., no more
207 		 * transfers will follow)
208 		 */
209 		if ((sg_count + 1 == sgs) && (flags & TXRX_DEASSERT_CS))
210 			ctrl0 |= BM_SSP_CTRL0_IGNORE_CRC;
211 
212 		if (ssp->devid == IMX23_SSP) {
213 			ctrl0 &= ~BM_SSP_CTRL0_XFER_COUNT;
214 			ctrl0 |= min;
215 		}
216 
217 		dma_xfer[sg_count].pio[0] = ctrl0;
218 		dma_xfer[sg_count].pio[3] = min;
219 
220 		if (vmalloced_buf) {
221 			vm_page = vmalloc_to_page(buf);
222 			if (!vm_page) {
223 				ret = -ENOMEM;
224 				goto err_vmalloc;
225 			}
226 
227 			sg_init_table(&dma_xfer[sg_count].sg, 1);
228 			sg_set_page(&dma_xfer[sg_count].sg, vm_page,
229 				    min, offset_in_page(buf));
230 		} else {
231 			sg_init_one(&dma_xfer[sg_count].sg, buf, min);
232 		}
233 
234 		ret = dma_map_sg(ssp->dev, &dma_xfer[sg_count].sg, 1,
235 			(flags & TXRX_WRITE) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
236 
237 		len -= min;
238 		buf += min;
239 
240 		/* Queue the PIO register write transfer. */
241 		desc = dmaengine_prep_slave_sg(ssp->dmach,
242 				(struct scatterlist *)dma_xfer[sg_count].pio,
243 				(ssp->devid == IMX23_SSP) ? 1 : 4,
244 				DMA_TRANS_NONE,
245 				sg_count ? DMA_PREP_INTERRUPT : 0);
246 		if (!desc) {
247 			dev_err(ssp->dev,
248 				"Failed to get PIO reg. write descriptor.\n");
249 			ret = -EINVAL;
250 			goto err_mapped;
251 		}
252 
253 		desc = dmaengine_prep_slave_sg(ssp->dmach,
254 				&dma_xfer[sg_count].sg, 1,
255 				(flags & TXRX_WRITE) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM,
256 				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
257 
258 		if (!desc) {
259 			dev_err(ssp->dev,
260 				"Failed to get DMA data write descriptor.\n");
261 			ret = -EINVAL;
262 			goto err_mapped;
263 		}
264 	}
265 
266 	/*
267 	 * The last descriptor must have this callback,
268 	 * to finish the DMA transaction.
269 	 */
270 	desc->callback = mxs_ssp_dma_irq_callback;
271 	desc->callback_param = spi;
272 
273 	/* Start the transfer. */
274 	dmaengine_submit(desc);
275 	dma_async_issue_pending(ssp->dmach);
276 
277 	if (!wait_for_completion_timeout(&spi->c,
278 					 msecs_to_jiffies(SSP_TIMEOUT))) {
279 		dev_err(ssp->dev, "DMA transfer timeout\n");
280 		ret = -ETIMEDOUT;
281 		dmaengine_terminate_all(ssp->dmach);
282 		goto err_vmalloc;
283 	}
284 
285 	ret = 0;
286 
287 err_vmalloc:
288 	while (--sg_count >= 0) {
289 err_mapped:
290 		dma_unmap_sg(ssp->dev, &dma_xfer[sg_count].sg, 1,
291 			(flags & TXRX_WRITE) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
292 	}
293 
294 	kfree(dma_xfer);
295 
296 	return ret;
297 }
298 
299 static int mxs_spi_txrx_pio(struct mxs_spi *spi,
300 			    unsigned char *buf, int len,
301 			    unsigned int flags)
302 {
303 	struct mxs_ssp *ssp = &spi->ssp;
304 
305 	writel(BM_SSP_CTRL0_IGNORE_CRC,
306 	       ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR);
307 
308 	while (len--) {
309 		if (len == 0 && (flags & TXRX_DEASSERT_CS))
310 			writel(BM_SSP_CTRL0_IGNORE_CRC,
311 			       ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
312 
313 		if (ssp->devid == IMX23_SSP) {
314 			writel(BM_SSP_CTRL0_XFER_COUNT,
315 				ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR);
316 			writel(1,
317 				ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
318 		} else {
319 			writel(1, ssp->base + HW_SSP_XFER_SIZE);
320 		}
321 
322 		if (flags & TXRX_WRITE)
323 			writel(BM_SSP_CTRL0_READ,
324 				ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR);
325 		else
326 			writel(BM_SSP_CTRL0_READ,
327 				ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
328 
329 		writel(BM_SSP_CTRL0_RUN,
330 				ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
331 
332 		if (mxs_ssp_wait(spi, HW_SSP_CTRL0, BM_SSP_CTRL0_RUN, 1))
333 			return -ETIMEDOUT;
334 
335 		if (flags & TXRX_WRITE)
336 			writel(*buf, ssp->base + HW_SSP_DATA(ssp));
337 
338 		writel(BM_SSP_CTRL0_DATA_XFER,
339 			     ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
340 
341 		if (!(flags & TXRX_WRITE)) {
342 			if (mxs_ssp_wait(spi, HW_SSP_STATUS(ssp),
343 						BM_SSP_STATUS_FIFO_EMPTY, 0))
344 				return -ETIMEDOUT;
345 
346 			*buf = (readl(ssp->base + HW_SSP_DATA(ssp)) & 0xff);
347 		}
348 
349 		if (mxs_ssp_wait(spi, HW_SSP_CTRL0, BM_SSP_CTRL0_RUN, 0))
350 			return -ETIMEDOUT;
351 
352 		buf++;
353 	}
354 
355 	if (len <= 0)
356 		return 0;
357 
358 	return -ETIMEDOUT;
359 }
360 
361 static int mxs_spi_transfer_one(struct spi_master *master,
362 				struct spi_message *m)
363 {
364 	struct mxs_spi *spi = spi_master_get_devdata(master);
365 	struct mxs_ssp *ssp = &spi->ssp;
366 	struct spi_transfer *t;
367 	unsigned int flag;
368 	int status = 0;
369 
370 	/* Program CS register bits here, it will be used for all transfers. */
371 	writel(BM_SSP_CTRL0_WAIT_FOR_CMD | BM_SSP_CTRL0_WAIT_FOR_IRQ,
372 	       ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR);
373 	writel(mxs_spi_cs_to_reg(m->spi->chip_select),
374 	       ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
375 
376 	list_for_each_entry(t, &m->transfers, transfer_list) {
377 
378 		trace_spi_transfer_start(m, t);
379 
380 		status = mxs_spi_setup_transfer(m->spi, t);
381 		if (status)
382 			break;
383 
384 		/* De-assert on last transfer, inverted by cs_change flag */
385 		flag = (&t->transfer_list == m->transfers.prev) ^ t->cs_change ?
386 		       TXRX_DEASSERT_CS : 0;
387 
388 		/*
389 		 * Small blocks can be transfered via PIO.
390 		 * Measured by empiric means:
391 		 *
392 		 * dd if=/dev/mtdblock0 of=/dev/null bs=1024k count=1
393 		 *
394 		 * DMA only: 2.164808 seconds, 473.0KB/s
395 		 * Combined: 1.676276 seconds, 610.9KB/s
396 		 */
397 		if (t->len < 32) {
398 			writel(BM_SSP_CTRL1_DMA_ENABLE,
399 				ssp->base + HW_SSP_CTRL1(ssp) +
400 				STMP_OFFSET_REG_CLR);
401 
402 			if (t->tx_buf)
403 				status = mxs_spi_txrx_pio(spi,
404 						(void *)t->tx_buf,
405 						t->len, flag | TXRX_WRITE);
406 			if (t->rx_buf)
407 				status = mxs_spi_txrx_pio(spi,
408 						t->rx_buf, t->len,
409 						flag);
410 		} else {
411 			writel(BM_SSP_CTRL1_DMA_ENABLE,
412 				ssp->base + HW_SSP_CTRL1(ssp) +
413 				STMP_OFFSET_REG_SET);
414 
415 			if (t->tx_buf)
416 				status = mxs_spi_txrx_dma(spi,
417 						(void *)t->tx_buf, t->len,
418 						flag | TXRX_WRITE);
419 			if (t->rx_buf)
420 				status = mxs_spi_txrx_dma(spi,
421 						t->rx_buf, t->len,
422 						flag);
423 		}
424 
425 		trace_spi_transfer_stop(m, t);
426 
427 		if (status) {
428 			stmp_reset_block(ssp->base);
429 			break;
430 		}
431 
432 		m->actual_length += t->len;
433 	}
434 
435 	m->status = status;
436 	spi_finalize_current_message(master);
437 
438 	return status;
439 }
440 
441 static int mxs_spi_runtime_suspend(struct device *dev)
442 {
443 	struct spi_master *master = dev_get_drvdata(dev);
444 	struct mxs_spi *spi = spi_master_get_devdata(master);
445 	struct mxs_ssp *ssp = &spi->ssp;
446 	int ret;
447 
448 	clk_disable_unprepare(ssp->clk);
449 
450 	ret = pinctrl_pm_select_idle_state(dev);
451 	if (ret) {
452 		int ret2 = clk_prepare_enable(ssp->clk);
453 
454 		if (ret2)
455 			dev_warn(dev, "Failed to reenable clock after failing pinctrl request (pinctrl: %d, clk: %d)\n",
456 				 ret, ret2);
457 	}
458 
459 	return ret;
460 }
461 
462 static int mxs_spi_runtime_resume(struct device *dev)
463 {
464 	struct spi_master *master = dev_get_drvdata(dev);
465 	struct mxs_spi *spi = spi_master_get_devdata(master);
466 	struct mxs_ssp *ssp = &spi->ssp;
467 	int ret;
468 
469 	ret = pinctrl_pm_select_default_state(dev);
470 	if (ret)
471 		return ret;
472 
473 	ret = clk_prepare_enable(ssp->clk);
474 	if (ret)
475 		pinctrl_pm_select_idle_state(dev);
476 
477 	return ret;
478 }
479 
480 static int __maybe_unused mxs_spi_suspend(struct device *dev)
481 {
482 	struct spi_master *master = dev_get_drvdata(dev);
483 	int ret;
484 
485 	ret = spi_master_suspend(master);
486 	if (ret)
487 		return ret;
488 
489 	if (!pm_runtime_suspended(dev))
490 		return mxs_spi_runtime_suspend(dev);
491 	else
492 		return 0;
493 }
494 
495 static int __maybe_unused mxs_spi_resume(struct device *dev)
496 {
497 	struct spi_master *master = dev_get_drvdata(dev);
498 	int ret;
499 
500 	if (!pm_runtime_suspended(dev))
501 		ret = mxs_spi_runtime_resume(dev);
502 	else
503 		ret = 0;
504 	if (ret)
505 		return ret;
506 
507 	ret = spi_master_resume(master);
508 	if (ret < 0 && !pm_runtime_suspended(dev))
509 		mxs_spi_runtime_suspend(dev);
510 
511 	return ret;
512 }
513 
514 static const struct dev_pm_ops mxs_spi_pm = {
515 	SET_RUNTIME_PM_OPS(mxs_spi_runtime_suspend,
516 			   mxs_spi_runtime_resume, NULL)
517 	SET_SYSTEM_SLEEP_PM_OPS(mxs_spi_suspend, mxs_spi_resume)
518 };
519 
520 static const struct of_device_id mxs_spi_dt_ids[] = {
521 	{ .compatible = "fsl,imx23-spi", .data = (void *) IMX23_SSP, },
522 	{ .compatible = "fsl,imx28-spi", .data = (void *) IMX28_SSP, },
523 	{ /* sentinel */ }
524 };
525 MODULE_DEVICE_TABLE(of, mxs_spi_dt_ids);
526 
527 static int mxs_spi_probe(struct platform_device *pdev)
528 {
529 	const struct of_device_id *of_id =
530 			of_match_device(mxs_spi_dt_ids, &pdev->dev);
531 	struct device_node *np = pdev->dev.of_node;
532 	struct spi_master *master;
533 	struct mxs_spi *spi;
534 	struct mxs_ssp *ssp;
535 	struct clk *clk;
536 	void __iomem *base;
537 	int devid, clk_freq;
538 	int ret = 0, irq_err;
539 
540 	/*
541 	 * Default clock speed for the SPI core. 160MHz seems to
542 	 * work reasonably well with most SPI flashes, so use this
543 	 * as a default. Override with "clock-frequency" DT prop.
544 	 */
545 	const int clk_freq_default = 160000000;
546 
547 	irq_err = platform_get_irq(pdev, 0);
548 	if (irq_err < 0)
549 		return irq_err;
550 
551 	base = devm_platform_ioremap_resource(pdev, 0);
552 	if (IS_ERR(base))
553 		return PTR_ERR(base);
554 
555 	clk = devm_clk_get(&pdev->dev, NULL);
556 	if (IS_ERR(clk))
557 		return PTR_ERR(clk);
558 
559 	devid = (enum mxs_ssp_id) of_id->data;
560 	ret = of_property_read_u32(np, "clock-frequency",
561 				   &clk_freq);
562 	if (ret)
563 		clk_freq = clk_freq_default;
564 
565 	master = spi_alloc_master(&pdev->dev, sizeof(*spi));
566 	if (!master)
567 		return -ENOMEM;
568 
569 	platform_set_drvdata(pdev, master);
570 
571 	master->transfer_one_message = mxs_spi_transfer_one;
572 	master->bits_per_word_mask = SPI_BPW_MASK(8);
573 	master->mode_bits = SPI_CPOL | SPI_CPHA;
574 	master->num_chipselect = 3;
575 	master->dev.of_node = np;
576 	master->flags = SPI_MASTER_HALF_DUPLEX;
577 	master->auto_runtime_pm = true;
578 
579 	spi = spi_master_get_devdata(master);
580 	ssp = &spi->ssp;
581 	ssp->dev = &pdev->dev;
582 	ssp->clk = clk;
583 	ssp->base = base;
584 	ssp->devid = devid;
585 
586 	init_completion(&spi->c);
587 
588 	ret = devm_request_irq(&pdev->dev, irq_err, mxs_ssp_irq_handler, 0,
589 			       dev_name(&pdev->dev), ssp);
590 	if (ret)
591 		goto out_master_free;
592 
593 	ssp->dmach = dma_request_chan(&pdev->dev, "rx-tx");
594 	if (IS_ERR(ssp->dmach)) {
595 		dev_err(ssp->dev, "Failed to request DMA\n");
596 		ret = PTR_ERR(ssp->dmach);
597 		goto out_master_free;
598 	}
599 
600 	pm_runtime_enable(ssp->dev);
601 	if (!pm_runtime_enabled(ssp->dev)) {
602 		ret = mxs_spi_runtime_resume(ssp->dev);
603 		if (ret < 0) {
604 			dev_err(ssp->dev, "runtime resume failed\n");
605 			goto out_dma_release;
606 		}
607 	}
608 
609 	ret = pm_runtime_get_sync(ssp->dev);
610 	if (ret < 0) {
611 		dev_err(ssp->dev, "runtime_get_sync failed\n");
612 		goto out_pm_runtime_disable;
613 	}
614 
615 	clk_set_rate(ssp->clk, clk_freq);
616 
617 	ret = stmp_reset_block(ssp->base);
618 	if (ret)
619 		goto out_pm_runtime_put;
620 
621 	ret = devm_spi_register_master(&pdev->dev, master);
622 	if (ret) {
623 		dev_err(&pdev->dev, "Cannot register SPI master, %d\n", ret);
624 		goto out_pm_runtime_put;
625 	}
626 
627 	pm_runtime_put(ssp->dev);
628 
629 	return 0;
630 
631 out_pm_runtime_put:
632 	pm_runtime_put(ssp->dev);
633 out_pm_runtime_disable:
634 	pm_runtime_disable(ssp->dev);
635 out_dma_release:
636 	dma_release_channel(ssp->dmach);
637 out_master_free:
638 	spi_master_put(master);
639 	return ret;
640 }
641 
642 static int mxs_spi_remove(struct platform_device *pdev)
643 {
644 	struct spi_master *master;
645 	struct mxs_spi *spi;
646 	struct mxs_ssp *ssp;
647 
648 	master = platform_get_drvdata(pdev);
649 	spi = spi_master_get_devdata(master);
650 	ssp = &spi->ssp;
651 
652 	pm_runtime_disable(&pdev->dev);
653 	if (!pm_runtime_status_suspended(&pdev->dev))
654 		mxs_spi_runtime_suspend(&pdev->dev);
655 
656 	dma_release_channel(ssp->dmach);
657 
658 	return 0;
659 }
660 
661 static struct platform_driver mxs_spi_driver = {
662 	.probe	= mxs_spi_probe,
663 	.remove	= mxs_spi_remove,
664 	.driver	= {
665 		.name	= DRIVER_NAME,
666 		.of_match_table = mxs_spi_dt_ids,
667 		.pm = &mxs_spi_pm,
668 	},
669 };
670 
671 module_platform_driver(mxs_spi_driver);
672 
673 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
674 MODULE_DESCRIPTION("MXS SPI master driver");
675 MODULE_LICENSE("GPL");
676 MODULE_ALIAS("platform:mxs-spi");
677