summaryrefslogtreecommitdiffstats
path: root/drivers/spi/spi-mxs.c
blob: 6ac95a2a21cef53bc7817c8403047e3b565ed478 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
// SPDX-License-Identifier: GPL-2.0+
//
// Freescale MXS SPI master driver
//
// Copyright 2012 DENX Software Engineering, GmbH.
// Copyright 2012 Freescale Semiconductor, Inc.
// Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
//
// Rework and transition to new API by:
// Marek Vasut <marex@denx.de>
//
// Based on previous attempt by:
// Fabio Estevam <fabio.estevam@freescale.com>
//
// Based on code from U-Boot bootloader by:
// Marek Vasut <marex@denx.de>
//
// Based on spi-stmp.c, which is:
// Author: Dmitry Pervushin <dimka@embeddedalley.com>

#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/highmem.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/completion.h>
#include <linux/gpio.h>
#include <linux/regulator/consumer.h>
#include <linux/pm_runtime.h>
#include <linux/module.h>
#include <linux/stmp_device.h>
#include <linux/spi/spi.h>
#include <linux/spi/mxs-spi.h>

#define DRIVER_NAME		"mxs-spi"

/* Use 10S timeout for very long transfers, it should suffice. */
#define SSP_TIMEOUT		10000

#define SG_MAXLEN		0xff00

/*
 * Flags for txrx functions.  More efficient that using an argument register for
 * each one.
 */
#define TXRX_WRITE		(1<<0)	/* This is a write */
#define TXRX_DEASSERT_CS	(1<<1)	/* De-assert CS at end of txrx */

struct mxs_spi {
	struct mxs_ssp		ssp;
	struct completion	c;
	unsigned int		sck;	/* Rate requested (vs actual) */
};

static int mxs_spi_setup_transfer(struct spi_device *dev,
				  const struct spi_transfer *t)
{
	struct mxs_spi *spi = spi_master_get_devdata(dev->master);
	struct mxs_ssp *ssp = &spi->ssp;
	const unsigned int hz = min(dev->max_speed_hz, t->speed_hz);

	if (hz == 0) {
		dev_err(&dev->dev, "SPI clock rate of zero not allowed\n");
		return -EINVAL;
	}

	if (hz != spi->sck) {
		mxs_ssp_set_clk_rate(ssp, hz);
		/*
		 * Save requested rate, hz, rather than the actual rate,
		 * ssp->clk_rate.  Otherwise we would set the rate every transfer
		 * when the actual rate is not quite the same as requested rate.
		 */
		spi->sck = hz;
		/*
		 * Perhaps we should return an error if the actual clock is
		 * nowhere close to what was requested?
		 */
	}

	writel(BM_SSP_CTRL0_LOCK_CS,
		ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);

	writel(BF_SSP_CTRL1_SSP_MODE(BV_SSP_CTRL1_SSP_MODE__SPI) |
	       BF_SSP_CTRL1_WORD_LENGTH(BV_SSP_CTRL1_WORD_LENGTH__EIGHT_BITS) |
	       ((dev->mode & SPI_CPOL) ? BM_SSP_CTRL1_POLARITY : 0) |
	       ((dev->mode & SPI_CPHA) ? BM_SSP_CTRL1_PHASE : 0),
	       ssp->base + HW_SSP_CTRL1(ssp));

	writel(0x0, ssp->base + HW_SSP_CMD0);
	writel(0x0, ssp->base + HW_SSP_CMD1);

	return 0;
}

static u32 mxs_spi_cs_to_reg(unsigned cs)
{
	u32 select = 0;

	/*
	 * i.MX28 Datasheet: 17.10.1: HW_SSP_CTRL0
	 *
	 * The bits BM_SSP_CTRL0_WAIT_FOR_CMD and BM_SSP_CTRL0_WAIT_FOR_IRQ
	 * in HW_SSP_CTRL0 register do have multiple usage, please refer to
	 * the datasheet for further details. In SPI mode, they are used to
	 * toggle the chip-select lines (nCS pins).
	 */
	if (cs & 1)
		select |= BM_SSP_CTRL0_WAIT_FOR_CMD;
	if (cs & 2)
		select |= BM_SSP_CTRL0_WAIT_FOR_IRQ;

	return select;
}

static int mxs_ssp_wait(struct mxs_spi *spi, int offset, int mask, bool set)
{
	const unsigned long timeout = jiffies + msecs_to_jiffies(SSP_TIMEOUT);
	struct mxs_ssp *ssp = &spi->ssp;
	u32 reg;

	do {
		reg = readl_relaxed(ssp->base + offset);

		if (!set)
			reg = ~reg;

		reg &= mask;

		if (reg == mask)
			return 0;
	} while (time_before(jiffies, timeout));

	return -ETIMEDOUT;
}

static void mxs_ssp_dma_irq_callback(void *param)
{
	struct mxs_spi *spi = param;

	complete(&spi->c);
}

static irqreturn_t mxs_ssp_irq_handler(int irq, void *dev_id)
{
	struct mxs_ssp *ssp = dev_id;

	dev_err(ssp->dev, "%s[%i] CTRL1=%08x STATUS=%08x\n",
		__func__, __LINE__,
		readl(ssp->base + HW_SSP_CTRL1(ssp)),
		readl(ssp->base + HW_SSP_STATUS(ssp)));
	return IRQ_HANDLED;
}

static int mxs_spi_txrx_dma(struct mxs_spi *spi,
			    unsigned char *buf, int len,
			    unsigned int flags)
{
	struct mxs_ssp *ssp = &spi->ssp;
	struct dma_async_tx_descriptor *desc = NULL;
	const bool vmalloced_buf = is_vmalloc_addr(buf);
	const int desc_len = vmalloced_buf ? PAGE_SIZE : SG_MAXLEN;
	const int sgs = DIV_ROUND_UP(len, desc_len);
	int sg_count;
	int min, ret;
	u32 ctrl0;
	struct page *vm_page;
	struct {
		u32			pio[4];
		struct scatterlist	sg;
	} *dma_xfer;

	if (!len)
		return -EINVAL;

	dma_xfer = kcalloc(sgs, sizeof(*dma_xfer), GFP_KERNEL);
	if (!dma_xfer)
		return -ENOMEM;

	reinit_completion(&spi->c);

	/* Chip select was already programmed into CTRL0 */
	ctrl0 = readl(ssp->base + HW_SSP_CTRL0);
	ctrl0 &= ~(BM_SSP_CTRL0_XFER_COUNT | BM_SSP_CTRL0_IGNORE_CRC |
		 BM_SSP_CTRL0_READ);
	ctrl0 |= BM_SSP_CTRL0_DATA_XFER;

	if (!(flags & TXRX_WRITE))
		ctrl0 |= BM_SSP_CTRL0_READ;

	/* Queue the DMA data transfer. */
	for (sg_count = 0; sg_count < sgs; sg_count++) {
		/* Prepare the transfer descriptor. */
		min = min(len, desc_len);

		/*
		 * De-assert CS on last segment if flag is set (i.e., no more
		 * transfers will follow)
		 */
		if ((sg_count + 1 == sgs) && (flags & TXRX_DEASSERT_CS))
			ctrl0 |= BM_SSP_CTRL0_IGNORE_CRC;

		if (ssp->devid == IMX23_SSP) {
			ctrl0 &= ~BM_SSP_CTRL0_XFER_COUNT;
			ctrl0 |= min;
		}

		dma_xfer[sg_count].pio[0] = ctrl0;
		dma_xfer[sg_count].pio[3] = min;

		if (vmalloced_buf) {
			vm_page = vmalloc_to_page(buf);
			if (!vm_page) {
				ret = -ENOMEM;
				goto err_vmalloc;
			}

			sg_init_table(&dma_xfer[sg_count].sg, 1);
			sg_set_page(&dma_xfer[sg_count].sg, vm_page,
				    min, offset_in_page(buf));
		} else {
			sg_init_one(&dma_xfer[sg_count].sg, buf, min);
		}

		ret = dma_map_sg(ssp->dev, &dma_xfer[sg_count].sg, 1,
			(flags & TXRX_WRITE) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);

		len -= min;
		buf += min;

		/* Queue the PIO register write transfer. */
		desc = dmaengine_prep_slave_sg(ssp->dmach,
				(struct scatterlist *)dma_xfer[sg_count].pio,
				(ssp->devid == IMX23_SSP) ? 1 : 4,
				DMA_TRANS_NONE,
				sg_count ? DMA_PREP_INTERRUPT : 0);
		if (!desc) {
			dev_err(ssp->dev,
				"Failed to get PIO reg. write descriptor.\n");
			ret = -EINVAL;
			goto err_mapped;
		}

		desc = dmaengine_prep_slave_sg(ssp->dmach,
				&dma_xfer[sg_count].sg, 1,
				(flags & TXRX_WRITE) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM,
				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);

		if (!desc) {
			dev_err(ssp->dev,
				"Failed to get DMA data write descriptor.\n");
			ret = -EINVAL;
			goto err_mapped;
		}
	}

	/*
	 * The last descriptor must have this callback,
	 * to finish the DMA transaction.
	 */
	desc->callback = mxs_ssp_dma_irq_callback;
	desc->callback_param = spi;

	/* Start the transfer. */
	dmaengine_submit(desc);
	dma_async_issue_pending(ssp->dmach);

	if (!wait_for_completion_timeout(&spi->c,
					 msecs_to_jiffies(SSP_TIMEOUT))) {
		dev_err(ssp->dev, "DMA transfer timeout\n");
		ret = -ETIMEDOUT;
		dmaengine_terminate_all(ssp->dmach);
		goto err_vmalloc;
	}

	ret = 0;

err_vmalloc:
	while (--sg_count >= 0) {
err_mapped:
		dma_unmap_sg(ssp->dev, &dma_xfer[sg_count].sg, 1,
			(flags & TXRX_WRITE) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
	}

	kfree(dma_xfer);

	return ret;
}

static int mxs_spi_txrx_pio(struct mxs_spi *spi,
			    unsigned char *buf, int len,
			    unsigned int flags)
{
	struct mxs_ssp *ssp = &spi->ssp;

	writel(BM_SSP_CTRL0_IGNORE_CRC,
	       ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR);

	while (len--) {
		if (len == 0 && (flags & TXRX_DEASSERT_CS))
			writel(BM_SSP_CTRL0_IGNORE_CRC,
			       ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);

		if (ssp->devid == IMX23_SSP) {
			writel(BM_SSP_CTRL0_XFER_COUNT,
				ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR);
			writel(1,
				ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
		} else {
			writel(1, ssp->base + HW_SSP_XFER_SIZE);
		}

		if (flags & TXRX_WRITE)
			writel(BM_SSP_CTRL0_READ,
				ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR);
		else
			writel(BM_SSP_CTRL0_READ,
				ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);

		writel(BM_SSP_CTRL0_RUN,
				ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);

		if (mxs_ssp_wait(spi, HW_SSP_CTRL0, BM_SSP_CTRL0_RUN, 1))
			return -ETIMEDOUT;

		if (flags & TXRX_WRITE)
			writel(*buf, ssp->base + HW_SSP_DATA(ssp));

		writel(BM_SSP_CTRL0_DATA_XFER,
			     ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);

		if (!(flags & TXRX_WRITE)) {
			if (mxs_ssp_wait(spi, HW_SSP_STATUS(ssp),
						BM_SSP_STATUS_FIFO_EMPTY, 0))
				return -ETIMEDOUT;

			*buf = (readl(ssp->base + HW_SSP_DATA(ssp)) & 0xff);
		}

		if (mxs_ssp_wait(spi, HW_SSP_CTRL0, BM_SSP_CTRL0_RUN, 0))
			return -ETIMEDOUT;

		buf++;
	}

	if (len <= 0)
		return 0;

	return -ETIMEDOUT;
}

static int mxs_spi_transfer_one(struct spi_master *master,
				struct spi_message *m)
{
	struct mxs_spi *spi = spi_master_get_devdata(master);
	struct mxs_ssp *ssp = &spi->ssp;
	struct spi_transfer *t;
	unsigned int flag;
	int status = 0;

	/* Program CS register bits here, it will be used for all transfers. */
	writel(BM_SSP_CTRL0_WAIT_FOR_CMD | BM_SSP_CTRL0_WAIT_FOR_IRQ,
	       ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR);
	writel(mxs_spi_cs_to_reg(m->spi->chip_select),
	       ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);

	list_for_each_entry(t, &m->transfers, transfer_list) {

		status = mxs_spi_setup_transfer(m->spi, t);
		if (status)
			break;

		/* De-assert on last transfer, inverted by cs_change flag */
		flag = (&t->transfer_list == m->transfers.prev) ^ t->cs_change ?
		       TXRX_DEASSERT_CS : 0;

		/*
		 * Small blocks can be transfered via PIO.
		 * Measured by empiric means:
		 *
		 * dd if=/dev/mtdblock0 of=/dev/null bs=1024k count=1
		 *
		 * DMA only: 2.164808 seconds, 473.0KB/s
		 * Combined: 1.676276 seconds, 610.9KB/s
		 */
		if (t->len < 32) {
			writel(BM_SSP_CTRL1_DMA_ENABLE,
				ssp->base + HW_SSP_CTRL1(ssp) +
				STMP_OFFSET_REG_CLR);

			if (t->tx_buf)
				status = mxs_spi_txrx_pio(spi,
						(void *)t->tx_buf,
						t->len, flag | TXRX_WRITE);
			if (t->rx_buf)
				status = mxs_spi_txrx_pio(spi,
						t->rx_buf, t->len,
						flag);
		} else {
			writel(BM_SSP_CTRL1_DMA_ENABLE,
				ssp->base + HW_SSP_CTRL1(ssp) +
				STMP_OFFSET_REG_SET);

			if (t->tx_buf)
				status = mxs_spi_txrx_dma(spi,
						(void *)t->tx_buf, t->len,
						flag | TXRX_WRITE);
			if (t->rx_buf)
				status = mxs_spi_txrx_dma(spi,
						t->rx_buf, t->len,
						flag);
		}

		if (status) {
			stmp_reset_block(ssp->base);
			break;
		}

		m->actual_length += t->len;
	}

	m->status = status;
	spi_finalize_current_message(master);

	return status;
}

static int mxs_spi_runtime_suspend(struct device *dev)
{
	struct spi_master *master = dev_get_drvdata(dev);
	struct mxs_spi *spi = spi_master_get_devdata(master);
	struct mxs_ssp *ssp = &spi->ssp;
	int ret;

	clk_disable_unprepare(ssp->clk);

	ret = pinctrl_pm_select_idle_state(dev);
	if (ret) {
		int ret2 = clk_prepare_enable(ssp->clk);

		if (ret2)
			dev_warn(dev, "Failed to reenable clock after failing pinctrl request (pinctrl: %d, clk: %d)\n",
				 ret, ret2);
	}

	return ret;
}

static int mxs_spi_runtime_resume(struct device *dev)
{
	struct spi_master *master = dev_get_drvdata(dev);
	struct mxs_spi *spi = spi_master_get_devdata(master);
	struct mxs_ssp *ssp = &spi->ssp;
	int ret;

	ret = pinctrl_pm_select_default_state(dev);
	if (ret)
		return ret;

	ret = clk_prepare_enable(ssp->clk);
	if (ret)
		pinctrl_pm_select_idle_state(dev);

	return ret;
}

static int __maybe_unused mxs_spi_suspend(struct device *dev)
{
	struct spi_master *master = dev_get_drvdata(dev);
	int ret;

	ret = spi_master_suspend(master);
	if (ret)
		return ret;

	if (!pm_runtime_suspended(dev))
		return mxs_spi_runtime_suspend(dev);
	else
		return 0;
}

static int __maybe_unused mxs_spi_resume(struct device *dev)
{
	struct spi_master *master = dev_get_drvdata(dev);
	int ret;

	if (!pm_runtime_suspended(dev))
		ret = mxs_spi_runtime_resume(dev);
	else
		ret = 0;
	if (ret)
		return ret;

	ret = spi_master_resume(master);
	if (ret < 0 && !pm_runtime_suspended(dev))
		mxs_spi_runtime_suspend(dev);

	return ret;
}

static const struct dev_pm_ops mxs_spi_pm = {
	SET_RUNTIME_PM_OPS(mxs_spi_runtime_suspend,
			   mxs_spi_runtime_resume, NULL)
	SET_SYSTEM_SLEEP_PM_OPS(mxs_spi_suspend, mxs_spi_resume)
};

static const struct of_device_id mxs_spi_dt_ids[] = {
	{ .compatible = "fsl,imx23-spi", .data = (void *) IMX23_SSP, },
	{ .compatible = "fsl,imx28-spi", .data = (void *) IMX28_SSP, },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mxs_spi_dt_ids);

static int mxs_spi_probe(struct platform_device *pdev)
{
	const struct of_device_id *of_id =
			of_match_device(mxs_spi_dt_ids, &pdev->dev);
	struct device_node *np = pdev->dev.of_node;
	struct spi_master *master;
	struct mxs_spi *spi;
	struct mxs_ssp *ssp;
	struct resource *iores;
	struct clk *clk;
	void __iomem *base;
	int devid, clk_freq;
	int ret = 0, irq_err;

	/*
	 * Default clock speed for the SPI core. 160MHz seems to
	 * work reasonably well with most SPI flashes, so use this
	 * as a default. Override with "clock-frequency" DT prop.
	 */
	const int clk_freq_default = 160000000;

	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	irq_err = platform_get_irq(pdev, 0);
	if (irq_err < 0)
		return irq_err;

	base = devm_ioremap_resource(&pdev->dev, iores);
	if (IS_ERR(base))
		return PTR_ERR(base);

	clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(clk))
		return PTR_ERR(clk);

	devid = (enum mxs_ssp_id) of_id->data;
	ret = of_property_read_u32(np, "clock-frequency",
				   &clk_freq);
	if (ret)
		clk_freq = clk_freq_default;

	master = spi_alloc_master(&pdev->dev, sizeof(*spi));
	if (!master)
		return -ENOMEM;

	platform_set_drvdata(pdev, master);

	master->transfer_one_message = mxs_spi_transfer_one;
	master->bits_per_word_mask = SPI_BPW_MASK(8);
	master->mode_bits = SPI_CPOL | SPI_CPHA;
	master->num_chipselect = 3;
	master->dev.of_node = np;
	master->flags = SPI_MASTER_HALF_DUPLEX;
	master->auto_runtime_pm = true;

	spi = spi_master_get_devdata(master);
	ssp = &spi->ssp;
	ssp->dev = &pdev->dev;
	ssp->clk = clk;
	ssp->base = base;
	ssp->devid = devid;

	init_completion(&spi->c);

	ret = devm_request_irq(&pdev->dev, irq_err, mxs_ssp_irq_handler, 0,
			       dev_name(&pdev->dev), ssp);
	if (ret)
		goto out_master_free;

	ssp->dmach = dma_request_slave_channel(&pdev->dev, "rx-tx");
	if (!ssp->dmach) {
		dev_err(ssp->dev, "Failed to request DMA\n");
		ret = -ENODEV;
		goto out_master_free;
	}

	pm_runtime_enable(ssp->dev);
	if (!pm_runtime_enabled(ssp->dev)) {
		ret = mxs_spi_runtime_resume(ssp->dev);
		if (ret < 0) {
			dev_err(ssp->dev, "runtime resume failed\n");
			goto out_dma_release;
		}
	}

	ret = pm_runtime_get_sync(ssp->dev);
	if (ret < 0) {
		dev_err(ssp->dev, "runtime_get_sync failed\n");
		goto out_pm_runtime_disable;
	}

	clk_set_rate(ssp->clk, clk_freq);

	ret = stmp_reset_block(ssp->base);
	if (ret)
		goto out_pm_runtime_put;

	ret = devm_spi_register_master(&pdev->dev, master);
	if (ret) {
		dev_err(&pdev->dev, "Cannot register SPI master, %d\n", ret);
		goto out_pm_runtime_put;
	}

	pm_runtime_put(ssp->dev);

	return 0;

out_pm_runtime_put:
	pm_runtime_put(ssp->dev);
out_pm_runtime_disable:
	pm_runtime_disable(ssp->dev);
out_dma_release:
	dma_release_channel(ssp->dmach);
out_master_free:
	spi_master_put(master);
	return ret;
}

static int mxs_spi_remove(struct platform_device *pdev)
{
	struct spi_master *master;
	struct mxs_spi *spi;
	struct mxs_ssp *ssp;

	master = platform_get_drvdata(pdev);
	spi = spi_master_get_devdata(master);
	ssp = &spi->ssp;

	pm_runtime_disable(&pdev->dev);
	if (!pm_runtime_status_suspended(&pdev->dev))
		mxs_spi_runtime_suspend(&pdev->dev);

	dma_release_channel(ssp->dmach);

	return 0;
}

static struct platform_driver mxs_spi_driver = {
	.probe	= mxs_spi_probe,
	.remove	= mxs_spi_remove,
	.driver	= {
		.name	= DRIVER_NAME,
		.of_match_table = mxs_spi_dt_ids,
		.pm = &mxs_spi_pm,
	},
};

module_platform_driver(mxs_spi_driver);

MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
MODULE_DESCRIPTION("MXS SPI master driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:mxs-spi");
OpenPOWER on IntegriCloud