xref: /openbmc/linux/sound/soc/img/img-i2s-out.c (revision e7f127b2) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * IMG I2S output controller driver
4  *
5  * Copyright (C) 2015 Imagination Technologies Ltd.
6  *
7  * Author: Damien Horsley <Damien.Horsley@imgtec.com>
8  */
9 
10 #include <linux/clk.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/platform_device.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/reset.h>
18 
19 #include <sound/core.h>
20 #include <sound/dmaengine_pcm.h>
21 #include <sound/initval.h>
22 #include <sound/pcm.h>
23 #include <sound/pcm_params.h>
24 #include <sound/soc.h>
25 
26 #define IMG_I2S_OUT_TX_FIFO			0x0
27 
28 #define IMG_I2S_OUT_CTL				0x4
29 #define IMG_I2S_OUT_CTL_DATA_EN_MASK		BIT(24)
30 #define IMG_I2S_OUT_CTL_ACTIVE_CHAN_MASK	0xffe000
31 #define IMG_I2S_OUT_CTL_ACTIVE_CHAN_SHIFT	13
32 #define IMG_I2S_OUT_CTL_FRM_SIZE_MASK		BIT(8)
33 #define IMG_I2S_OUT_CTL_MASTER_MASK		BIT(6)
34 #define IMG_I2S_OUT_CTL_CLK_MASK		BIT(5)
35 #define IMG_I2S_OUT_CTL_CLK_EN_MASK		BIT(4)
36 #define IMG_I2S_OUT_CTL_FRM_CLK_POL_MASK	BIT(3)
37 #define IMG_I2S_OUT_CTL_BCLK_POL_MASK		BIT(2)
38 #define IMG_I2S_OUT_CTL_ME_MASK			BIT(0)
39 
40 #define IMG_I2S_OUT_CH_CTL			0x4
41 #define IMG_I2S_OUT_CHAN_CTL_CH_MASK		BIT(11)
42 #define IMG_I2S_OUT_CHAN_CTL_LT_MASK		BIT(10)
43 #define IMG_I2S_OUT_CHAN_CTL_FMT_MASK		0xf0
44 #define IMG_I2S_OUT_CHAN_CTL_FMT_SHIFT		4
45 #define IMG_I2S_OUT_CHAN_CTL_JUST_MASK		BIT(3)
46 #define IMG_I2S_OUT_CHAN_CTL_CLKT_MASK		BIT(1)
47 #define IMG_I2S_OUT_CHAN_CTL_ME_MASK		BIT(0)
48 
49 #define IMG_I2S_OUT_CH_STRIDE			0x20
50 
51 struct img_i2s_out {
52 	void __iomem *base;
53 	struct clk *clk_sys;
54 	struct clk *clk_ref;
55 	struct snd_dmaengine_dai_dma_data dma_data;
56 	struct device *dev;
57 	unsigned int max_i2s_chan;
58 	void __iomem *channel_base;
59 	bool force_clk_active;
60 	unsigned int active_channels;
61 	struct reset_control *rst;
62 	struct snd_soc_dai_driver dai_driver;
63 	u32 suspend_ctl;
64 	u32 *suspend_ch_ctl;
65 };
66 
67 static int img_i2s_out_runtime_suspend(struct device *dev)
68 {
69 	struct img_i2s_out *i2s = dev_get_drvdata(dev);
70 
71 	clk_disable_unprepare(i2s->clk_ref);
72 	clk_disable_unprepare(i2s->clk_sys);
73 
74 	return 0;
75 }
76 
77 static int img_i2s_out_runtime_resume(struct device *dev)
78 {
79 	struct img_i2s_out *i2s = dev_get_drvdata(dev);
80 	int ret;
81 
82 	ret = clk_prepare_enable(i2s->clk_sys);
83 	if (ret) {
84 		dev_err(dev, "clk_enable failed: %d\n", ret);
85 		return ret;
86 	}
87 
88 	ret = clk_prepare_enable(i2s->clk_ref);
89 	if (ret) {
90 		dev_err(dev, "clk_enable failed: %d\n", ret);
91 		clk_disable_unprepare(i2s->clk_sys);
92 		return ret;
93 	}
94 
95 	return 0;
96 }
97 
98 static inline void img_i2s_out_writel(struct img_i2s_out *i2s, u32 val,
99 					u32 reg)
100 {
101 	writel(val, i2s->base + reg);
102 }
103 
104 static inline u32 img_i2s_out_readl(struct img_i2s_out *i2s, u32 reg)
105 {
106 	return readl(i2s->base + reg);
107 }
108 
109 static inline void img_i2s_out_ch_writel(struct img_i2s_out *i2s,
110 					u32 chan, u32 val, u32 reg)
111 {
112 	writel(val, i2s->channel_base + (chan * IMG_I2S_OUT_CH_STRIDE) + reg);
113 }
114 
115 static inline u32 img_i2s_out_ch_readl(struct img_i2s_out *i2s, u32 chan,
116 					u32 reg)
117 {
118 	return readl(i2s->channel_base + (chan * IMG_I2S_OUT_CH_STRIDE) + reg);
119 }
120 
121 static inline void img_i2s_out_ch_disable(struct img_i2s_out *i2s, u32 chan)
122 {
123 	u32 reg;
124 
125 	reg = img_i2s_out_ch_readl(i2s, chan, IMG_I2S_OUT_CH_CTL);
126 	reg &= ~IMG_I2S_OUT_CHAN_CTL_ME_MASK;
127 	img_i2s_out_ch_writel(i2s, chan, reg, IMG_I2S_OUT_CH_CTL);
128 }
129 
130 static inline void img_i2s_out_ch_enable(struct img_i2s_out *i2s, u32 chan)
131 {
132 	u32 reg;
133 
134 	reg = img_i2s_out_ch_readl(i2s, chan, IMG_I2S_OUT_CH_CTL);
135 	reg |= IMG_I2S_OUT_CHAN_CTL_ME_MASK;
136 	img_i2s_out_ch_writel(i2s, chan, reg, IMG_I2S_OUT_CH_CTL);
137 }
138 
139 static inline void img_i2s_out_disable(struct img_i2s_out *i2s)
140 {
141 	u32 reg;
142 
143 	reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
144 	reg &= ~IMG_I2S_OUT_CTL_ME_MASK;
145 	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
146 }
147 
148 static inline void img_i2s_out_enable(struct img_i2s_out *i2s)
149 {
150 	u32 reg;
151 
152 	reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
153 	reg |= IMG_I2S_OUT_CTL_ME_MASK;
154 	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
155 }
156 
157 static void img_i2s_out_reset(struct img_i2s_out *i2s)
158 {
159 	int i;
160 	u32 core_ctl, chan_ctl;
161 
162 	core_ctl = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL) &
163 			~IMG_I2S_OUT_CTL_ME_MASK &
164 			~IMG_I2S_OUT_CTL_DATA_EN_MASK;
165 
166 	if (!i2s->force_clk_active)
167 		core_ctl &= ~IMG_I2S_OUT_CTL_CLK_EN_MASK;
168 
169 	chan_ctl = img_i2s_out_ch_readl(i2s, 0, IMG_I2S_OUT_CH_CTL) &
170 			~IMG_I2S_OUT_CHAN_CTL_ME_MASK;
171 
172 	reset_control_assert(i2s->rst);
173 	reset_control_deassert(i2s->rst);
174 
175 	for (i = 0; i < i2s->max_i2s_chan; i++)
176 		img_i2s_out_ch_writel(i2s, i, chan_ctl, IMG_I2S_OUT_CH_CTL);
177 
178 	for (i = 0; i < i2s->active_channels; i++)
179 		img_i2s_out_ch_enable(i2s, i);
180 
181 	img_i2s_out_writel(i2s, core_ctl, IMG_I2S_OUT_CTL);
182 	img_i2s_out_enable(i2s);
183 }
184 
185 static int img_i2s_out_trigger(struct snd_pcm_substream *substream, int cmd,
186 	struct snd_soc_dai *dai)
187 {
188 	struct img_i2s_out *i2s = snd_soc_dai_get_drvdata(dai);
189 	u32 reg;
190 
191 	switch (cmd) {
192 	case SNDRV_PCM_TRIGGER_START:
193 	case SNDRV_PCM_TRIGGER_RESUME:
194 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
195 		reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
196 		if (!i2s->force_clk_active)
197 			reg |= IMG_I2S_OUT_CTL_CLK_EN_MASK;
198 		reg |= IMG_I2S_OUT_CTL_DATA_EN_MASK;
199 		img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
200 		break;
201 	case SNDRV_PCM_TRIGGER_STOP:
202 	case SNDRV_PCM_TRIGGER_SUSPEND:
203 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
204 		img_i2s_out_reset(i2s);
205 		break;
206 	default:
207 		return -EINVAL;
208 	}
209 
210 	return 0;
211 }
212 
213 static int img_i2s_out_hw_params(struct snd_pcm_substream *substream,
214 	struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
215 {
216 	struct img_i2s_out *i2s = snd_soc_dai_get_drvdata(dai);
217 	unsigned int channels, i2s_channels;
218 	long pre_div_a, pre_div_b, diff_a, diff_b, rate, clk_rate;
219 	int i;
220 	u32 reg, control_mask, control_set = 0;
221 	snd_pcm_format_t format;
222 
223 	rate = params_rate(params);
224 	format = params_format(params);
225 	channels = params_channels(params);
226 	i2s_channels = channels / 2;
227 
228 	if (format != SNDRV_PCM_FORMAT_S32_LE)
229 		return -EINVAL;
230 
231 	if ((channels < 2) ||
232 	    (channels > (i2s->max_i2s_chan * 2)) ||
233 	    (channels % 2))
234 		return -EINVAL;
235 
236 	pre_div_a = clk_round_rate(i2s->clk_ref, rate * 256);
237 	if (pre_div_a < 0)
238 		return pre_div_a;
239 	pre_div_b = clk_round_rate(i2s->clk_ref, rate * 384);
240 	if (pre_div_b < 0)
241 		return pre_div_b;
242 
243 	diff_a = abs((pre_div_a / 256) - rate);
244 	diff_b = abs((pre_div_b / 384) - rate);
245 
246 	/* If diffs are equal, use lower clock rate */
247 	if (diff_a > diff_b)
248 		clk_set_rate(i2s->clk_ref, pre_div_b);
249 	else
250 		clk_set_rate(i2s->clk_ref, pre_div_a);
251 
252 	/*
253 	 * Another driver (eg alsa machine driver) may have rejected the above
254 	 * change. Get the current rate and set the register bit according to
255 	 * the new minimum diff
256 	 */
257 	clk_rate = clk_get_rate(i2s->clk_ref);
258 
259 	diff_a = abs((clk_rate / 256) - rate);
260 	diff_b = abs((clk_rate / 384) - rate);
261 
262 	if (diff_a > diff_b)
263 		control_set |= IMG_I2S_OUT_CTL_CLK_MASK;
264 
265 	control_set |= ((i2s_channels - 1) <<
266 		       IMG_I2S_OUT_CTL_ACTIVE_CHAN_SHIFT) &
267 		       IMG_I2S_OUT_CTL_ACTIVE_CHAN_MASK;
268 
269 	control_mask = IMG_I2S_OUT_CTL_CLK_MASK |
270 		       IMG_I2S_OUT_CTL_ACTIVE_CHAN_MASK;
271 
272 	img_i2s_out_disable(i2s);
273 
274 	reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
275 	reg = (reg & ~control_mask) | control_set;
276 	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
277 
278 	for (i = 0; i < i2s_channels; i++)
279 		img_i2s_out_ch_enable(i2s, i);
280 
281 	for (; i < i2s->max_i2s_chan; i++)
282 		img_i2s_out_ch_disable(i2s, i);
283 
284 	img_i2s_out_enable(i2s);
285 
286 	i2s->active_channels = i2s_channels;
287 
288 	return 0;
289 }
290 
291 static int img_i2s_out_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
292 {
293 	struct img_i2s_out *i2s = snd_soc_dai_get_drvdata(dai);
294 	int i, ret;
295 	bool force_clk_active;
296 	u32 chan_control_mask, control_mask, chan_control_set = 0;
297 	u32 reg, control_set = 0;
298 
299 	force_clk_active = ((fmt & SND_SOC_DAIFMT_CLOCK_MASK) ==
300 			SND_SOC_DAIFMT_CONT);
301 
302 	if (force_clk_active)
303 		control_set |= IMG_I2S_OUT_CTL_CLK_EN_MASK;
304 
305 	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
306 	case SND_SOC_DAIFMT_CBM_CFM:
307 		break;
308 	case SND_SOC_DAIFMT_CBS_CFS:
309 		control_set |= IMG_I2S_OUT_CTL_MASTER_MASK;
310 		break;
311 	default:
312 		return -EINVAL;
313 	}
314 
315 	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
316 	case SND_SOC_DAIFMT_NB_NF:
317 		control_set |= IMG_I2S_OUT_CTL_BCLK_POL_MASK;
318 		break;
319 	case SND_SOC_DAIFMT_NB_IF:
320 		control_set |= IMG_I2S_OUT_CTL_BCLK_POL_MASK;
321 		control_set |= IMG_I2S_OUT_CTL_FRM_CLK_POL_MASK;
322 		break;
323 	case SND_SOC_DAIFMT_IB_NF:
324 		break;
325 	case SND_SOC_DAIFMT_IB_IF:
326 		control_set |= IMG_I2S_OUT_CTL_FRM_CLK_POL_MASK;
327 		break;
328 	default:
329 		return -EINVAL;
330 	}
331 
332 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
333 	case SND_SOC_DAIFMT_I2S:
334 		chan_control_set |= IMG_I2S_OUT_CHAN_CTL_CLKT_MASK;
335 		break;
336 	case SND_SOC_DAIFMT_LEFT_J:
337 		break;
338 	default:
339 		return -EINVAL;
340 	}
341 
342 	control_mask = IMG_I2S_OUT_CTL_CLK_EN_MASK |
343 		       IMG_I2S_OUT_CTL_MASTER_MASK |
344 		       IMG_I2S_OUT_CTL_BCLK_POL_MASK |
345 		       IMG_I2S_OUT_CTL_FRM_CLK_POL_MASK;
346 
347 	chan_control_mask = IMG_I2S_OUT_CHAN_CTL_CLKT_MASK;
348 
349 	ret = pm_runtime_get_sync(i2s->dev);
350 	if (ret < 0) {
351 		pm_runtime_put_noidle(i2s->dev);
352 		return ret;
353 	}
354 
355 	img_i2s_out_disable(i2s);
356 
357 	reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
358 	reg = (reg & ~control_mask) | control_set;
359 	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
360 
361 	for (i = 0; i < i2s->active_channels; i++)
362 		img_i2s_out_ch_disable(i2s, i);
363 
364 	for (i = 0; i < i2s->max_i2s_chan; i++) {
365 		reg = img_i2s_out_ch_readl(i2s, i, IMG_I2S_OUT_CH_CTL);
366 		reg = (reg & ~chan_control_mask) | chan_control_set;
367 		img_i2s_out_ch_writel(i2s, i, reg, IMG_I2S_OUT_CH_CTL);
368 	}
369 
370 	for (i = 0; i < i2s->active_channels; i++)
371 		img_i2s_out_ch_enable(i2s, i);
372 
373 	img_i2s_out_enable(i2s);
374 	pm_runtime_put(i2s->dev);
375 
376 	i2s->force_clk_active = force_clk_active;
377 
378 	return 0;
379 }
380 
381 static const struct snd_soc_dai_ops img_i2s_out_dai_ops = {
382 	.trigger = img_i2s_out_trigger,
383 	.hw_params = img_i2s_out_hw_params,
384 	.set_fmt = img_i2s_out_set_fmt
385 };
386 
387 static int img_i2s_out_dai_probe(struct snd_soc_dai *dai)
388 {
389 	struct img_i2s_out *i2s = snd_soc_dai_get_drvdata(dai);
390 
391 	snd_soc_dai_init_dma_data(dai, &i2s->dma_data, NULL);
392 
393 	return 0;
394 }
395 
396 static const struct snd_soc_component_driver img_i2s_out_component = {
397 	.name = "img-i2s-out"
398 };
399 
400 static int img_i2s_out_dma_prepare_slave_config(struct snd_pcm_substream *st,
401 	struct snd_pcm_hw_params *params, struct dma_slave_config *sc)
402 {
403 	unsigned int i2s_channels = params_channels(params) / 2;
404 	struct snd_soc_pcm_runtime *rtd = st->private_data;
405 	struct snd_dmaengine_dai_dma_data *dma_data;
406 	int ret;
407 
408 	dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), st);
409 
410 	ret = snd_hwparams_to_dma_slave_config(st, params, sc);
411 	if (ret)
412 		return ret;
413 
414 	sc->dst_addr = dma_data->addr;
415 	sc->dst_addr_width = dma_data->addr_width;
416 	sc->dst_maxburst = 4 * i2s_channels;
417 
418 	return 0;
419 }
420 
421 static const struct snd_dmaengine_pcm_config img_i2s_out_dma_config = {
422 	.prepare_slave_config = img_i2s_out_dma_prepare_slave_config
423 };
424 
425 static int img_i2s_out_probe(struct platform_device *pdev)
426 {
427 	struct img_i2s_out *i2s;
428 	struct resource *res;
429 	void __iomem *base;
430 	int i, ret;
431 	unsigned int max_i2s_chan_pow_2;
432 	u32 reg;
433 	struct device *dev = &pdev->dev;
434 
435 	i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
436 	if (!i2s)
437 		return -ENOMEM;
438 
439 	platform_set_drvdata(pdev, i2s);
440 
441 	i2s->dev = &pdev->dev;
442 
443 	base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
444 	if (IS_ERR(base))
445 		return PTR_ERR(base);
446 
447 	i2s->base = base;
448 
449 	if (of_property_read_u32(pdev->dev.of_node, "img,i2s-channels",
450 			&i2s->max_i2s_chan)) {
451 		dev_err(&pdev->dev, "No img,i2s-channels property\n");
452 		return -EINVAL;
453 	}
454 
455 	max_i2s_chan_pow_2 = 1 << get_count_order(i2s->max_i2s_chan);
456 
457 	i2s->channel_base = base + (max_i2s_chan_pow_2 * 0x20);
458 
459 	i2s->rst = devm_reset_control_get_exclusive(&pdev->dev, "rst");
460 	if (IS_ERR(i2s->rst))
461 		return dev_err_probe(&pdev->dev, PTR_ERR(i2s->rst),
462 				     "No top level reset found\n");
463 
464 	i2s->clk_sys = devm_clk_get(&pdev->dev, "sys");
465 	if (IS_ERR(i2s->clk_sys))
466 		return dev_err_probe(dev, PTR_ERR(i2s->clk_sys),
467 				     "Failed to acquire clock 'sys'\n");
468 
469 	i2s->clk_ref = devm_clk_get(&pdev->dev, "ref");
470 	if (IS_ERR(i2s->clk_ref))
471 		return dev_err_probe(dev, PTR_ERR(i2s->clk_ref),
472 				     "Failed to acquire clock 'ref'\n");
473 
474 	i2s->suspend_ch_ctl = devm_kcalloc(dev,
475 		i2s->max_i2s_chan, sizeof(*i2s->suspend_ch_ctl), GFP_KERNEL);
476 	if (!i2s->suspend_ch_ctl)
477 		return -ENOMEM;
478 
479 	pm_runtime_enable(&pdev->dev);
480 	if (!pm_runtime_enabled(&pdev->dev)) {
481 		ret = img_i2s_out_runtime_resume(&pdev->dev);
482 		if (ret)
483 			goto err_pm_disable;
484 	}
485 	ret = pm_runtime_get_sync(&pdev->dev);
486 	if (ret < 0) {
487 		pm_runtime_put_noidle(&pdev->dev);
488 		goto err_suspend;
489 	}
490 
491 	reg = IMG_I2S_OUT_CTL_FRM_SIZE_MASK;
492 	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
493 
494 	reg = IMG_I2S_OUT_CHAN_CTL_JUST_MASK |
495 		IMG_I2S_OUT_CHAN_CTL_LT_MASK |
496 		IMG_I2S_OUT_CHAN_CTL_CH_MASK |
497 		(8 << IMG_I2S_OUT_CHAN_CTL_FMT_SHIFT);
498 
499 	for (i = 0; i < i2s->max_i2s_chan; i++)
500 		img_i2s_out_ch_writel(i2s, i, reg, IMG_I2S_OUT_CH_CTL);
501 
502 	img_i2s_out_reset(i2s);
503 	pm_runtime_put(&pdev->dev);
504 
505 	i2s->active_channels = 1;
506 	i2s->dma_data.addr = res->start + IMG_I2S_OUT_TX_FIFO;
507 	i2s->dma_data.addr_width = 4;
508 	i2s->dma_data.maxburst = 4;
509 
510 	i2s->dai_driver.probe = img_i2s_out_dai_probe;
511 	i2s->dai_driver.playback.channels_min = 2;
512 	i2s->dai_driver.playback.channels_max = i2s->max_i2s_chan * 2;
513 	i2s->dai_driver.playback.rates = SNDRV_PCM_RATE_8000_192000;
514 	i2s->dai_driver.playback.formats = SNDRV_PCM_FMTBIT_S32_LE;
515 	i2s->dai_driver.ops = &img_i2s_out_dai_ops;
516 
517 	ret = devm_snd_soc_register_component(&pdev->dev,
518 			&img_i2s_out_component, &i2s->dai_driver, 1);
519 	if (ret)
520 		goto err_suspend;
521 
522 	ret = devm_snd_dmaengine_pcm_register(&pdev->dev,
523 			&img_i2s_out_dma_config, 0);
524 	if (ret)
525 		goto err_suspend;
526 
527 	return 0;
528 
529 err_suspend:
530 	if (!pm_runtime_status_suspended(&pdev->dev))
531 		img_i2s_out_runtime_suspend(&pdev->dev);
532 err_pm_disable:
533 	pm_runtime_disable(&pdev->dev);
534 
535 	return ret;
536 }
537 
538 static int img_i2s_out_dev_remove(struct platform_device *pdev)
539 {
540 	pm_runtime_disable(&pdev->dev);
541 	if (!pm_runtime_status_suspended(&pdev->dev))
542 		img_i2s_out_runtime_suspend(&pdev->dev);
543 
544 	return 0;
545 }
546 
547 #ifdef CONFIG_PM_SLEEP
548 static int img_i2s_out_suspend(struct device *dev)
549 {
550 	struct img_i2s_out *i2s = dev_get_drvdata(dev);
551 	int i, ret;
552 	u32 reg;
553 
554 	if (pm_runtime_status_suspended(dev)) {
555 		ret = img_i2s_out_runtime_resume(dev);
556 		if (ret)
557 			return ret;
558 	}
559 
560 	for (i = 0; i < i2s->max_i2s_chan; i++) {
561 		reg = img_i2s_out_ch_readl(i2s, i, IMG_I2S_OUT_CH_CTL);
562 		i2s->suspend_ch_ctl[i] = reg;
563 	}
564 
565 	i2s->suspend_ctl = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
566 
567 	img_i2s_out_runtime_suspend(dev);
568 
569 	return 0;
570 }
571 
572 static int img_i2s_out_resume(struct device *dev)
573 {
574 	struct img_i2s_out *i2s = dev_get_drvdata(dev);
575 	int i, ret;
576 	u32 reg;
577 
578 	ret = img_i2s_out_runtime_resume(dev);
579 	if (ret)
580 		return ret;
581 
582 	for (i = 0; i < i2s->max_i2s_chan; i++) {
583 		reg = i2s->suspend_ch_ctl[i];
584 		img_i2s_out_ch_writel(i2s, i, reg, IMG_I2S_OUT_CH_CTL);
585 	}
586 
587 	img_i2s_out_writel(i2s, i2s->suspend_ctl, IMG_I2S_OUT_CTL);
588 
589 	if (pm_runtime_status_suspended(dev))
590 		img_i2s_out_runtime_suspend(dev);
591 
592 	return 0;
593 }
594 #endif
595 
596 static const struct of_device_id img_i2s_out_of_match[] = {
597 	{ .compatible = "img,i2s-out" },
598 	{}
599 };
600 MODULE_DEVICE_TABLE(of, img_i2s_out_of_match);
601 
602 static const struct dev_pm_ops img_i2s_out_pm_ops = {
603 	SET_RUNTIME_PM_OPS(img_i2s_out_runtime_suspend,
604 			   img_i2s_out_runtime_resume, NULL)
605 	SET_SYSTEM_SLEEP_PM_OPS(img_i2s_out_suspend, img_i2s_out_resume)
606 };
607 
608 static struct platform_driver img_i2s_out_driver = {
609 	.driver = {
610 		.name = "img-i2s-out",
611 		.of_match_table = img_i2s_out_of_match,
612 		.pm = &img_i2s_out_pm_ops
613 	},
614 	.probe = img_i2s_out_probe,
615 	.remove = img_i2s_out_dev_remove
616 };
617 module_platform_driver(img_i2s_out_driver);
618 
619 MODULE_AUTHOR("Damien Horsley <Damien.Horsley@imgtec.com>");
620 MODULE_DESCRIPTION("IMG I2S Output Driver");
621 MODULE_LICENSE("GPL v2");
622