summaryrefslogtreecommitdiff
path: root/sound/soc/img/img-i2s-out.c
blob: 30a95bcef2db97ebd9c2904c1caf697109309d30 (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
/*
 * IMG I2S output controller driver
 *
 * Copyright (C) 2015 Imagination Technologies Ltd.
 *
 * Author: Damien Horsley <Damien.Horsley@imgtec.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 */

#include <linux/clk.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>

#include <sound/core.h>
#include <sound/dmaengine_pcm.h>
#include <sound/initval.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>

#define IMG_I2S_OUT_TX_FIFO			0x0

#define IMG_I2S_OUT_CTL				0x4
#define IMG_I2S_OUT_CTL_DATA_EN_MASK		BIT(24)
#define IMG_I2S_OUT_CTL_ACTIVE_CHAN_MASK	0xffe000
#define IMG_I2S_OUT_CTL_ACTIVE_CHAN_SHIFT	13
#define IMG_I2S_OUT_CTL_FRM_SIZE_MASK		BIT(8)
#define IMG_I2S_OUT_CTL_MASTER_MASK		BIT(6)
#define IMG_I2S_OUT_CTL_CLK_MASK		BIT(5)
#define IMG_I2S_OUT_CTL_CLK_EN_MASK		BIT(4)
#define IMG_I2S_OUT_CTL_FRM_CLK_POL_MASK	BIT(3)
#define IMG_I2S_OUT_CTL_BCLK_POL_MASK		BIT(2)
#define IMG_I2S_OUT_CTL_ME_MASK			BIT(0)

#define IMG_I2S_OUT_CH_CTL			0x4
#define IMG_I2S_OUT_CHAN_CTL_CH_MASK		BIT(11)
#define IMG_I2S_OUT_CHAN_CTL_LT_MASK		BIT(10)
#define IMG_I2S_OUT_CHAN_CTL_FMT_MASK		0xf0
#define IMG_I2S_OUT_CHAN_CTL_FMT_SHIFT		4
#define IMG_I2S_OUT_CHAN_CTL_JUST_MASK		BIT(3)
#define IMG_I2S_OUT_CHAN_CTL_CLKT_MASK		BIT(1)
#define IMG_I2S_OUT_CHAN_CTL_ME_MASK		BIT(0)

#define IMG_I2S_OUT_CH_STRIDE			0x20

struct img_i2s_out {
	void __iomem *base;
	struct clk *clk_sys;
	struct clk *clk_ref;
	struct snd_dmaengine_dai_dma_data dma_data;
	struct device *dev;
	unsigned int max_i2s_chan;
	void __iomem *channel_base;
	bool force_clk_active;
	unsigned int active_channels;
	struct reset_control *rst;
	struct snd_soc_dai_driver dai_driver;
	u32 suspend_ctl;
	u32 *suspend_ch_ctl;
};

static int img_i2s_out_runtime_suspend(struct device *dev)
{
	struct img_i2s_out *i2s = dev_get_drvdata(dev);

	clk_disable_unprepare(i2s->clk_ref);
	clk_disable_unprepare(i2s->clk_sys);

	return 0;
}

static int img_i2s_out_runtime_resume(struct device *dev)
{
	struct img_i2s_out *i2s = dev_get_drvdata(dev);
	int ret;

	ret = clk_prepare_enable(i2s->clk_sys);
	if (ret) {
		dev_err(dev, "clk_enable failed: %d\n", ret);
		return ret;
	}

	ret = clk_prepare_enable(i2s->clk_ref);
	if (ret) {
		dev_err(dev, "clk_enable failed: %d\n", ret);
		clk_disable_unprepare(i2s->clk_sys);
		return ret;
	}

	return 0;
}

static inline void img_i2s_out_writel(struct img_i2s_out *i2s, u32 val,
					u32 reg)
{
	writel(val, i2s->base + reg);
}

static inline u32 img_i2s_out_readl(struct img_i2s_out *i2s, u32 reg)
{
	return readl(i2s->base + reg);
}

static inline void img_i2s_out_ch_writel(struct img_i2s_out *i2s,
					u32 chan, u32 val, u32 reg)
{
	writel(val, i2s->channel_base + (chan * IMG_I2S_OUT_CH_STRIDE) + reg);
}

static inline u32 img_i2s_out_ch_readl(struct img_i2s_out *i2s, u32 chan,
					u32 reg)
{
	return readl(i2s->channel_base + (chan * IMG_I2S_OUT_CH_STRIDE) + reg);
}

static inline void img_i2s_out_ch_disable(struct img_i2s_out *i2s, u32 chan)
{
	u32 reg;

	reg = img_i2s_out_ch_readl(i2s, chan, IMG_I2S_OUT_CH_CTL);
	reg &= ~IMG_I2S_OUT_CHAN_CTL_ME_MASK;
	img_i2s_out_ch_writel(i2s, chan, reg, IMG_I2S_OUT_CH_CTL);
}

static inline void img_i2s_out_ch_enable(struct img_i2s_out *i2s, u32 chan)
{
	u32 reg;

	reg = img_i2s_out_ch_readl(i2s, chan, IMG_I2S_OUT_CH_CTL);
	reg |= IMG_I2S_OUT_CHAN_CTL_ME_MASK;
	img_i2s_out_ch_writel(i2s, chan, reg, IMG_I2S_OUT_CH_CTL);
}

static inline void img_i2s_out_disable(struct img_i2s_out *i2s)
{
	u32 reg;

	reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
	reg &= ~IMG_I2S_OUT_CTL_ME_MASK;
	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
}

static inline void img_i2s_out_enable(struct img_i2s_out *i2s)
{
	u32 reg;

	reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
	reg |= IMG_I2S_OUT_CTL_ME_MASK;
	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
}

static void img_i2s_out_reset(struct img_i2s_out *i2s)
{
	int i;
	u32 core_ctl, chan_ctl;

	core_ctl = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL) &
			~IMG_I2S_OUT_CTL_ME_MASK &
			~IMG_I2S_OUT_CTL_DATA_EN_MASK;

	if (!i2s->force_clk_active)
		core_ctl &= ~IMG_I2S_OUT_CTL_CLK_EN_MASK;

	chan_ctl = img_i2s_out_ch_readl(i2s, 0, IMG_I2S_OUT_CH_CTL) &
			~IMG_I2S_OUT_CHAN_CTL_ME_MASK;

	reset_control_assert(i2s->rst);
	reset_control_deassert(i2s->rst);

	for (i = 0; i < i2s->max_i2s_chan; i++)
		img_i2s_out_ch_writel(i2s, i, chan_ctl, IMG_I2S_OUT_CH_CTL);

	for (i = 0; i < i2s->active_channels; i++)
		img_i2s_out_ch_enable(i2s, i);

	img_i2s_out_writel(i2s, core_ctl, IMG_I2S_OUT_CTL);
	img_i2s_out_enable(i2s);
}

static int img_i2s_out_trigger(struct snd_pcm_substream *substream, int cmd,
	struct snd_soc_dai *dai)
{
	struct img_i2s_out *i2s = snd_soc_dai_get_drvdata(dai);
	u32 reg;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
		reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
		if (!i2s->force_clk_active)
			reg |= IMG_I2S_OUT_CTL_CLK_EN_MASK;
		reg |= IMG_I2S_OUT_CTL_DATA_EN_MASK;
		img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
		break;
	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		img_i2s_out_reset(i2s);
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static int img_i2s_out_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
{
	struct img_i2s_out *i2s = snd_soc_dai_get_drvdata(dai);
	unsigned int channels, i2s_channels;
	long pre_div_a, pre_div_b, diff_a, diff_b, rate, clk_rate;
	int i;
	u32 reg, control_mask, control_set = 0;
	snd_pcm_format_t format;

	rate = params_rate(params);
	format = params_format(params);
	channels = params_channels(params);
	i2s_channels = channels / 2;

	if (format != SNDRV_PCM_FORMAT_S32_LE)
		return -EINVAL;

	if ((channels < 2) ||
	    (channels > (i2s->max_i2s_chan * 2)) ||
	    (channels % 2))
		return -EINVAL;

	pre_div_a = clk_round_rate(i2s->clk_ref, rate * 256);
	if (pre_div_a < 0)
		return pre_div_a;
	pre_div_b = clk_round_rate(i2s->clk_ref, rate * 384);
	if (pre_div_b < 0)
		return pre_div_b;

	diff_a = abs((pre_div_a / 256) - rate);
	diff_b = abs((pre_div_b / 384) - rate);

	/* If diffs are equal, use lower clock rate */
	if (diff_a > diff_b)
		clk_set_rate(i2s->clk_ref, pre_div_b);
	else
		clk_set_rate(i2s->clk_ref, pre_div_a);

	/*
	 * Another driver (eg alsa machine driver) may have rejected the above
	 * change. Get the current rate and set the register bit according to
	 * the new minimum diff
	 */
	clk_rate = clk_get_rate(i2s->clk_ref);

	diff_a = abs((clk_rate / 256) - rate);
	diff_b = abs((clk_rate / 384) - rate);

	if (diff_a > diff_b)
		control_set |= IMG_I2S_OUT_CTL_CLK_MASK;

	control_set |= ((i2s_channels - 1) <<
		       IMG_I2S_OUT_CTL_ACTIVE_CHAN_SHIFT) &
		       IMG_I2S_OUT_CTL_ACTIVE_CHAN_MASK;

	control_mask = IMG_I2S_OUT_CTL_CLK_MASK |
		       IMG_I2S_OUT_CTL_ACTIVE_CHAN_MASK;

	img_i2s_out_disable(i2s);

	reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
	reg = (reg & ~control_mask) | control_set;
	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);

	for (i = 0; i < i2s_channels; i++)
		img_i2s_out_ch_enable(i2s, i);

	for (; i < i2s->max_i2s_chan; i++)
		img_i2s_out_ch_disable(i2s, i);

	img_i2s_out_enable(i2s);

	i2s->active_channels = i2s_channels;

	return 0;
}

static int img_i2s_out_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
{
	struct img_i2s_out *i2s = snd_soc_dai_get_drvdata(dai);
	int i, ret;
	bool force_clk_active;
	u32 chan_control_mask, control_mask, chan_control_set = 0;
	u32 reg, control_set = 0;

	force_clk_active = ((fmt & SND_SOC_DAIFMT_CLOCK_MASK) ==
			SND_SOC_DAIFMT_CONT);

	if (force_clk_active)
		control_set |= IMG_I2S_OUT_CTL_CLK_EN_MASK;

	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
	case SND_SOC_DAIFMT_CBM_CFM:
		break;
	case SND_SOC_DAIFMT_CBS_CFS:
		control_set |= IMG_I2S_OUT_CTL_MASTER_MASK;
		break;
	default:
		return -EINVAL;
	}

	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
	case SND_SOC_DAIFMT_NB_NF:
		control_set |= IMG_I2S_OUT_CTL_BCLK_POL_MASK;
		break;
	case SND_SOC_DAIFMT_NB_IF:
		control_set |= IMG_I2S_OUT_CTL_BCLK_POL_MASK;
		control_set |= IMG_I2S_OUT_CTL_FRM_CLK_POL_MASK;
		break;
	case SND_SOC_DAIFMT_IB_NF:
		break;
	case SND_SOC_DAIFMT_IB_IF:
		control_set |= IMG_I2S_OUT_CTL_FRM_CLK_POL_MASK;
		break;
	default:
		return -EINVAL;
	}

	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
	case SND_SOC_DAIFMT_I2S:
		chan_control_set |= IMG_I2S_OUT_CHAN_CTL_CLKT_MASK;
		break;
	case SND_SOC_DAIFMT_LEFT_J:
		break;
	default:
		return -EINVAL;
	}

	control_mask = IMG_I2S_OUT_CTL_CLK_EN_MASK |
		       IMG_I2S_OUT_CTL_MASTER_MASK |
		       IMG_I2S_OUT_CTL_BCLK_POL_MASK |
		       IMG_I2S_OUT_CTL_FRM_CLK_POL_MASK;

	chan_control_mask = IMG_I2S_OUT_CHAN_CTL_CLKT_MASK;

	ret = pm_runtime_get_sync(i2s->dev);
	if (ret < 0)
		return ret;

	img_i2s_out_disable(i2s);

	reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
	reg = (reg & ~control_mask) | control_set;
	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);

	for (i = 0; i < i2s->active_channels; i++)
		img_i2s_out_ch_disable(i2s, i);

	for (i = 0; i < i2s->max_i2s_chan; i++) {
		reg = img_i2s_out_ch_readl(i2s, i, IMG_I2S_OUT_CH_CTL);
		reg = (reg & ~chan_control_mask) | chan_control_set;
		img_i2s_out_ch_writel(i2s, i, reg, IMG_I2S_OUT_CH_CTL);
	}

	for (i = 0; i < i2s->active_channels; i++)
		img_i2s_out_ch_enable(i2s, i);

	img_i2s_out_enable(i2s);
	pm_runtime_put(i2s->dev);

	i2s->force_clk_active = force_clk_active;

	return 0;
}

static const struct snd_soc_dai_ops img_i2s_out_dai_ops = {
	.trigger = img_i2s_out_trigger,
	.hw_params = img_i2s_out_hw_params,
	.set_fmt = img_i2s_out_set_fmt
};

static int img_i2s_out_dai_probe(struct snd_soc_dai *dai)
{
	struct img_i2s_out *i2s = snd_soc_dai_get_drvdata(dai);

	snd_soc_dai_init_dma_data(dai, &i2s->dma_data, NULL);

	return 0;
}

static const struct snd_soc_component_driver img_i2s_out_component = {
	.name = "img-i2s-out"
};

static int img_i2s_out_dma_prepare_slave_config(struct snd_pcm_substream *st,
	struct snd_pcm_hw_params *params, struct dma_slave_config *sc)
{
	unsigned int i2s_channels = params_channels(params) / 2;
	struct snd_soc_pcm_runtime *rtd = st->private_data;
	struct snd_dmaengine_dai_dma_data *dma_data;
	int ret;

	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, st);

	ret = snd_hwparams_to_dma_slave_config(st, params, sc);
	if (ret)
		return ret;

	sc->dst_addr = dma_data->addr;
	sc->dst_addr_width = dma_data->addr_width;
	sc->dst_maxburst = 4 * i2s_channels;

	return 0;
}

static const struct snd_dmaengine_pcm_config img_i2s_out_dma_config = {
	.prepare_slave_config = img_i2s_out_dma_prepare_slave_config
};

static int img_i2s_out_probe(struct platform_device *pdev)
{
	struct img_i2s_out *i2s;
	struct resource *res;
	void __iomem *base;
	int i, ret;
	unsigned int max_i2s_chan_pow_2;
	u32 reg;
	struct device *dev = &pdev->dev;

	i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
	if (!i2s)
		return -ENOMEM;

	platform_set_drvdata(pdev, i2s);

	i2s->dev = &pdev->dev;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(base))
		return PTR_ERR(base);

	i2s->base = base;

	if (of_property_read_u32(pdev->dev.of_node, "img,i2s-channels",
			&i2s->max_i2s_chan)) {
		dev_err(&pdev->dev, "No img,i2s-channels property\n");
		return -EINVAL;
	}

	max_i2s_chan_pow_2 = 1 << get_count_order(i2s->max_i2s_chan);

	i2s->channel_base = base + (max_i2s_chan_pow_2 * 0x20);

	i2s->rst = devm_reset_control_get_exclusive(&pdev->dev, "rst");
	if (IS_ERR(i2s->rst)) {
		if (PTR_ERR(i2s->rst) != -EPROBE_DEFER)
			dev_err(&pdev->dev, "No top level reset found\n");
		return PTR_ERR(i2s->rst);
	}

	i2s->clk_sys = devm_clk_get(&pdev->dev, "sys");
	if (IS_ERR(i2s->clk_sys)) {
		if (PTR_ERR(i2s->clk_sys) != -EPROBE_DEFER)
			dev_err(dev, "Failed to acquire clock 'sys'\n");
		return PTR_ERR(i2s->clk_sys);
	}

	i2s->clk_ref = devm_clk_get(&pdev->dev, "ref");
	if (IS_ERR(i2s->clk_ref)) {
		if (PTR_ERR(i2s->clk_ref) != -EPROBE_DEFER)
			dev_err(dev, "Failed to acquire clock 'ref'\n");
		return PTR_ERR(i2s->clk_ref);
	}

	i2s->suspend_ch_ctl = devm_kzalloc(dev,
		sizeof(*i2s->suspend_ch_ctl) * i2s->max_i2s_chan, GFP_KERNEL);
	if (!i2s->suspend_ch_ctl)
		return -ENOMEM;

	pm_runtime_enable(&pdev->dev);
	if (!pm_runtime_enabled(&pdev->dev)) {
		ret = img_i2s_out_runtime_resume(&pdev->dev);
		if (ret)
			goto err_pm_disable;
	}
	ret = pm_runtime_get_sync(&pdev->dev);
	if (ret < 0)
		goto err_suspend;

	reg = IMG_I2S_OUT_CTL_FRM_SIZE_MASK;
	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);

	reg = IMG_I2S_OUT_CHAN_CTL_JUST_MASK |
		IMG_I2S_OUT_CHAN_CTL_LT_MASK |
		IMG_I2S_OUT_CHAN_CTL_CH_MASK |
		(8 << IMG_I2S_OUT_CHAN_CTL_FMT_SHIFT);

	for (i = 0; i < i2s->max_i2s_chan; i++)
		img_i2s_out_ch_writel(i2s, i, reg, IMG_I2S_OUT_CH_CTL);

	img_i2s_out_reset(i2s);
	pm_runtime_put(&pdev->dev);

	i2s->active_channels = 1;
	i2s->dma_data.addr = res->start + IMG_I2S_OUT_TX_FIFO;
	i2s->dma_data.addr_width = 4;
	i2s->dma_data.maxburst = 4;

	i2s->dai_driver.probe = img_i2s_out_dai_probe;
	i2s->dai_driver.playback.channels_min = 2;
	i2s->dai_driver.playback.channels_max = i2s->max_i2s_chan * 2;
	i2s->dai_driver.playback.rates = SNDRV_PCM_RATE_8000_192000;
	i2s->dai_driver.playback.formats = SNDRV_PCM_FMTBIT_S32_LE;
	i2s->dai_driver.ops = &img_i2s_out_dai_ops;

	ret = devm_snd_soc_register_component(&pdev->dev,
			&img_i2s_out_component, &i2s->dai_driver, 1);
	if (ret)
		goto err_suspend;

	ret = devm_snd_dmaengine_pcm_register(&pdev->dev,
			&img_i2s_out_dma_config, 0);
	if (ret)
		goto err_suspend;

	return 0;

err_suspend:
	if (!pm_runtime_status_suspended(&pdev->dev))
		img_i2s_out_runtime_suspend(&pdev->dev);
err_pm_disable:
	pm_runtime_disable(&pdev->dev);

	return ret;
}

static int img_i2s_out_dev_remove(struct platform_device *pdev)
{
	pm_runtime_disable(&pdev->dev);
	if (!pm_runtime_status_suspended(&pdev->dev))
		img_i2s_out_runtime_suspend(&pdev->dev);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int img_i2s_out_suspend(struct device *dev)
{
	struct img_i2s_out *i2s = dev_get_drvdata(dev);
	int i, ret;
	u32 reg;

	if (pm_runtime_status_suspended(dev)) {
		ret = img_i2s_out_runtime_resume(dev);
		if (ret)
			return ret;
	}

	for (i = 0; i < i2s->max_i2s_chan; i++) {
		reg = img_i2s_out_ch_readl(i2s, i, IMG_I2S_OUT_CH_CTL);
		i2s->suspend_ch_ctl[i] = reg;
	}

	i2s->suspend_ctl = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);

	img_i2s_out_runtime_suspend(dev);

	return 0;
}

static int img_i2s_out_resume(struct device *dev)
{
	struct img_i2s_out *i2s = dev_get_drvdata(dev);
	int i, ret;
	u32 reg;

	ret = img_i2s_out_runtime_resume(dev);
	if (ret)
		return ret;

	for (i = 0; i < i2s->max_i2s_chan; i++) {
		reg = i2s->suspend_ch_ctl[i];
		img_i2s_out_ch_writel(i2s, i, reg, IMG_I2S_OUT_CH_CTL);
	}

	img_i2s_out_writel(i2s, i2s->suspend_ctl, IMG_I2S_OUT_CTL);

	if (pm_runtime_status_suspended(dev))
		img_i2s_out_runtime_suspend(dev);

	return 0;
}
#endif

static const struct of_device_id img_i2s_out_of_match[] = {
	{ .compatible = "img,i2s-out" },
	{}
};
MODULE_DEVICE_TABLE(of, img_i2s_out_of_match);

static const struct dev_pm_ops img_i2s_out_pm_ops = {
	SET_RUNTIME_PM_OPS(img_i2s_out_runtime_suspend,
			   img_i2s_out_runtime_resume, NULL)
	SET_SYSTEM_SLEEP_PM_OPS(img_i2s_out_suspend, img_i2s_out_resume)
};

static struct platform_driver img_i2s_out_driver = {
	.driver = {
		.name = "img-i2s-out",
		.of_match_table = img_i2s_out_of_match,
		.pm = &img_i2s_out_pm_ops
	},
	.probe = img_i2s_out_probe,
	.remove = img_i2s_out_dev_remove
};
module_platform_driver(img_i2s_out_driver);

MODULE_AUTHOR("Damien Horsley <Damien.Horsley@imgtec.com>");
MODULE_DESCRIPTION("IMG I2S Output Driver");
MODULE_LICENSE("GPL v2");