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v6.2
  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
 51struct 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
 67static 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
 77static 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
 98static 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
104static inline u32 img_i2s_out_readl(struct img_i2s_out *i2s, u32 reg)
105{
106	return readl(i2s->base + reg);
107}
108
109static 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
115static 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
121static 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
130static 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
139static 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
148static 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
157static 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
185static 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
213static 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
291static 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_CLOCK_PROVIDER_MASK) {
306	case SND_SOC_DAIFMT_BC_FC:
307		break;
308	case SND_SOC_DAIFMT_BP_FP:
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_resume_and_get(i2s->dev);
350	if (ret < 0)
351		return ret;
352
353	img_i2s_out_disable(i2s);
354
355	reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
356	reg = (reg & ~control_mask) | control_set;
357	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
358
359	for (i = 0; i < i2s->active_channels; i++)
360		img_i2s_out_ch_disable(i2s, i);
361
362	for (i = 0; i < i2s->max_i2s_chan; i++) {
363		reg = img_i2s_out_ch_readl(i2s, i, IMG_I2S_OUT_CH_CTL);
364		reg = (reg & ~chan_control_mask) | chan_control_set;
365		img_i2s_out_ch_writel(i2s, i, reg, IMG_I2S_OUT_CH_CTL);
366	}
367
368	for (i = 0; i < i2s->active_channels; i++)
369		img_i2s_out_ch_enable(i2s, i);
370
371	img_i2s_out_enable(i2s);
372	pm_runtime_put(i2s->dev);
373
374	i2s->force_clk_active = force_clk_active;
375
376	return 0;
377}
378
379static const struct snd_soc_dai_ops img_i2s_out_dai_ops = {
380	.trigger = img_i2s_out_trigger,
381	.hw_params = img_i2s_out_hw_params,
382	.set_fmt = img_i2s_out_set_fmt
383};
384
385static int img_i2s_out_dai_probe(struct snd_soc_dai *dai)
386{
387	struct img_i2s_out *i2s = snd_soc_dai_get_drvdata(dai);
388
389	snd_soc_dai_init_dma_data(dai, &i2s->dma_data, NULL);
390
391	return 0;
392}
393
394static const struct snd_soc_component_driver img_i2s_out_component = {
395	.name = "img-i2s-out",
396	.legacy_dai_naming = 1,
397};
398
399static int img_i2s_out_dma_prepare_slave_config(struct snd_pcm_substream *st,
400	struct snd_pcm_hw_params *params, struct dma_slave_config *sc)
401{
402	unsigned int i2s_channels = params_channels(params) / 2;
403	struct snd_soc_pcm_runtime *rtd = st->private_data;
404	struct snd_dmaengine_dai_dma_data *dma_data;
405	int ret;
406
407	dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), st);
408
409	ret = snd_hwparams_to_dma_slave_config(st, params, sc);
410	if (ret)
411		return ret;
412
413	sc->dst_addr = dma_data->addr;
414	sc->dst_addr_width = dma_data->addr_width;
415	sc->dst_maxburst = 4 * i2s_channels;
416
417	return 0;
418}
419
420static const struct snd_dmaengine_pcm_config img_i2s_out_dma_config = {
421	.prepare_slave_config = img_i2s_out_dma_prepare_slave_config
422};
423
424static int img_i2s_out_probe(struct platform_device *pdev)
425{
426	struct img_i2s_out *i2s;
427	struct resource *res;
428	void __iomem *base;
429	int i, ret;
430	unsigned int max_i2s_chan_pow_2;
431	u32 reg;
432	struct device *dev = &pdev->dev;
433
434	i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
435	if (!i2s)
436		return -ENOMEM;
437
438	platform_set_drvdata(pdev, i2s);
439
440	i2s->dev = &pdev->dev;
441
442	base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
 
443	if (IS_ERR(base))
444		return PTR_ERR(base);
445
446	i2s->base = base;
447
448	if (of_property_read_u32(pdev->dev.of_node, "img,i2s-channels",
449			&i2s->max_i2s_chan)) {
450		dev_err(&pdev->dev, "No img,i2s-channels property\n");
451		return -EINVAL;
452	}
453
454	max_i2s_chan_pow_2 = 1 << get_count_order(i2s->max_i2s_chan);
455
456	i2s->channel_base = base + (max_i2s_chan_pow_2 * 0x20);
457
458	i2s->rst = devm_reset_control_get_exclusive(&pdev->dev, "rst");
459	if (IS_ERR(i2s->rst))
460		return dev_err_probe(&pdev->dev, PTR_ERR(i2s->rst),
461				     "No top level reset found\n");
 
 
462
463	i2s->clk_sys = devm_clk_get(&pdev->dev, "sys");
464	if (IS_ERR(i2s->clk_sys))
465		return dev_err_probe(dev, PTR_ERR(i2s->clk_sys),
466				     "Failed to acquire clock 'sys'\n");
 
 
467
468	i2s->clk_ref = devm_clk_get(&pdev->dev, "ref");
469	if (IS_ERR(i2s->clk_ref))
470		return dev_err_probe(dev, PTR_ERR(i2s->clk_ref),
471				     "Failed to acquire clock 'ref'\n");
472
473	i2s->suspend_ch_ctl = devm_kcalloc(dev,
474		i2s->max_i2s_chan, sizeof(*i2s->suspend_ch_ctl), GFP_KERNEL);
475	if (!i2s->suspend_ch_ctl)
476		return -ENOMEM;
477
478	pm_runtime_enable(&pdev->dev);
479	if (!pm_runtime_enabled(&pdev->dev)) {
480		ret = img_i2s_out_runtime_resume(&pdev->dev);
481		if (ret)
482			goto err_pm_disable;
483	}
484	ret = pm_runtime_resume_and_get(&pdev->dev);
485	if (ret < 0)
486		goto err_suspend;
 
487
488	reg = IMG_I2S_OUT_CTL_FRM_SIZE_MASK;
489	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
490
491	reg = IMG_I2S_OUT_CHAN_CTL_JUST_MASK |
492		IMG_I2S_OUT_CHAN_CTL_LT_MASK |
493		IMG_I2S_OUT_CHAN_CTL_CH_MASK |
494		(8 << IMG_I2S_OUT_CHAN_CTL_FMT_SHIFT);
495
496	for (i = 0; i < i2s->max_i2s_chan; i++)
497		img_i2s_out_ch_writel(i2s, i, reg, IMG_I2S_OUT_CH_CTL);
498
499	img_i2s_out_reset(i2s);
500	pm_runtime_put(&pdev->dev);
 
 
 
 
 
 
501
502	i2s->active_channels = 1;
503	i2s->dma_data.addr = res->start + IMG_I2S_OUT_TX_FIFO;
504	i2s->dma_data.addr_width = 4;
505	i2s->dma_data.maxburst = 4;
506
507	i2s->dai_driver.probe = img_i2s_out_dai_probe;
508	i2s->dai_driver.playback.channels_min = 2;
509	i2s->dai_driver.playback.channels_max = i2s->max_i2s_chan * 2;
510	i2s->dai_driver.playback.rates = SNDRV_PCM_RATE_8000_192000;
511	i2s->dai_driver.playback.formats = SNDRV_PCM_FMTBIT_S32_LE;
512	i2s->dai_driver.ops = &img_i2s_out_dai_ops;
513
514	ret = devm_snd_soc_register_component(&pdev->dev,
515			&img_i2s_out_component, &i2s->dai_driver, 1);
516	if (ret)
517		goto err_suspend;
518
519	ret = devm_snd_dmaengine_pcm_register(&pdev->dev,
520			&img_i2s_out_dma_config, 0);
521	if (ret)
522		goto err_suspend;
523
524	return 0;
525
526err_suspend:
527	if (!pm_runtime_status_suspended(&pdev->dev))
528		img_i2s_out_runtime_suspend(&pdev->dev);
529err_pm_disable:
530	pm_runtime_disable(&pdev->dev);
 
531
532	return ret;
533}
534
535static int img_i2s_out_dev_remove(struct platform_device *pdev)
536{
 
 
537	pm_runtime_disable(&pdev->dev);
538	if (!pm_runtime_status_suspended(&pdev->dev))
539		img_i2s_out_runtime_suspend(&pdev->dev);
540
541	return 0;
542}
543
544#ifdef CONFIG_PM_SLEEP
545static int img_i2s_out_suspend(struct device *dev)
546{
547	struct img_i2s_out *i2s = dev_get_drvdata(dev);
548	int i, ret;
549	u32 reg;
550
551	if (pm_runtime_status_suspended(dev)) {
552		ret = img_i2s_out_runtime_resume(dev);
553		if (ret)
554			return ret;
555	}
556
557	for (i = 0; i < i2s->max_i2s_chan; i++) {
558		reg = img_i2s_out_ch_readl(i2s, i, IMG_I2S_OUT_CH_CTL);
559		i2s->suspend_ch_ctl[i] = reg;
560	}
561
562	i2s->suspend_ctl = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
563
564	img_i2s_out_runtime_suspend(dev);
565
566	return 0;
567}
568
569static int img_i2s_out_resume(struct device *dev)
570{
571	struct img_i2s_out *i2s = dev_get_drvdata(dev);
572	int i, ret;
573	u32 reg;
574
575	ret = img_i2s_out_runtime_resume(dev);
576	if (ret)
577		return ret;
578
579	for (i = 0; i < i2s->max_i2s_chan; i++) {
580		reg = i2s->suspend_ch_ctl[i];
581		img_i2s_out_ch_writel(i2s, i, reg, IMG_I2S_OUT_CH_CTL);
582	}
583
584	img_i2s_out_writel(i2s, i2s->suspend_ctl, IMG_I2S_OUT_CTL);
585
586	if (pm_runtime_status_suspended(dev))
587		img_i2s_out_runtime_suspend(dev);
588
589	return 0;
590}
591#endif
592
593static const struct of_device_id img_i2s_out_of_match[] = {
594	{ .compatible = "img,i2s-out" },
595	{}
596};
597MODULE_DEVICE_TABLE(of, img_i2s_out_of_match);
598
599static const struct dev_pm_ops img_i2s_out_pm_ops = {
600	SET_RUNTIME_PM_OPS(img_i2s_out_runtime_suspend,
601			   img_i2s_out_runtime_resume, NULL)
602	SET_SYSTEM_SLEEP_PM_OPS(img_i2s_out_suspend, img_i2s_out_resume)
603};
604
605static struct platform_driver img_i2s_out_driver = {
606	.driver = {
607		.name = "img-i2s-out",
608		.of_match_table = img_i2s_out_of_match,
609		.pm = &img_i2s_out_pm_ops
610	},
611	.probe = img_i2s_out_probe,
612	.remove = img_i2s_out_dev_remove
613};
614module_platform_driver(img_i2s_out_driver);
615
616MODULE_AUTHOR("Damien Horsley <Damien.Horsley@imgtec.com>");
617MODULE_DESCRIPTION("IMG I2S Output Driver");
618MODULE_LICENSE("GPL v2");
v4.6
 
  1/*
  2 * IMG I2S output controller driver
  3 *
  4 * Copyright (C) 2015 Imagination Technologies Ltd.
  5 *
  6 * Author: Damien Horsley <Damien.Horsley@imgtec.com>
  7 *
  8 * This program is free software; you can redistribute it and/or modify it
  9 * under the terms and conditions of the GNU General Public License,
 10 * version 2, as published by the Free Software Foundation.
 11 */
 12
 13#include <linux/clk.h>
 14#include <linux/init.h>
 15#include <linux/kernel.h>
 16#include <linux/module.h>
 17#include <linux/of.h>
 18#include <linux/platform_device.h>
 19#include <linux/pm_runtime.h>
 20#include <linux/reset.h>
 21
 22#include <sound/core.h>
 23#include <sound/dmaengine_pcm.h>
 24#include <sound/initval.h>
 25#include <sound/pcm.h>
 26#include <sound/pcm_params.h>
 27#include <sound/soc.h>
 28
 29#define IMG_I2S_OUT_TX_FIFO			0x0
 30
 31#define IMG_I2S_OUT_CTL				0x4
 32#define IMG_I2S_OUT_CTL_DATA_EN_MASK		BIT(24)
 33#define IMG_I2S_OUT_CTL_ACTIVE_CHAN_MASK	0xffe000
 34#define IMG_I2S_OUT_CTL_ACTIVE_CHAN_SHIFT	13
 35#define IMG_I2S_OUT_CTL_FRM_SIZE_MASK		BIT(8)
 36#define IMG_I2S_OUT_CTL_MASTER_MASK		BIT(6)
 37#define IMG_I2S_OUT_CTL_CLK_MASK		BIT(5)
 38#define IMG_I2S_OUT_CTL_CLK_EN_MASK		BIT(4)
 39#define IMG_I2S_OUT_CTL_FRM_CLK_POL_MASK	BIT(3)
 40#define IMG_I2S_OUT_CTL_BCLK_POL_MASK		BIT(2)
 41#define IMG_I2S_OUT_CTL_ME_MASK			BIT(0)
 42
 43#define IMG_I2S_OUT_CH_CTL			0x4
 44#define IMG_I2S_OUT_CHAN_CTL_CH_MASK		BIT(11)
 45#define IMG_I2S_OUT_CHAN_CTL_LT_MASK		BIT(10)
 46#define IMG_I2S_OUT_CHAN_CTL_FMT_MASK		0xf0
 47#define IMG_I2S_OUT_CHAN_CTL_FMT_SHIFT		4
 48#define IMG_I2S_OUT_CHAN_CTL_JUST_MASK		BIT(3)
 49#define IMG_I2S_OUT_CHAN_CTL_CLKT_MASK		BIT(1)
 50#define IMG_I2S_OUT_CHAN_CTL_ME_MASK		BIT(0)
 51
 52#define IMG_I2S_OUT_CH_STRIDE			0x20
 53
 54struct img_i2s_out {
 55	void __iomem *base;
 56	struct clk *clk_sys;
 57	struct clk *clk_ref;
 58	struct snd_dmaengine_dai_dma_data dma_data;
 59	struct device *dev;
 60	unsigned int max_i2s_chan;
 61	void __iomem *channel_base;
 62	bool force_clk_active;
 63	unsigned int active_channels;
 64	struct reset_control *rst;
 65	struct snd_soc_dai_driver dai_driver;
 
 
 66};
 67
 68static int img_i2s_out_suspend(struct device *dev)
 69{
 70	struct img_i2s_out *i2s = dev_get_drvdata(dev);
 71
 72	if (!i2s->force_clk_active)
 73		clk_disable_unprepare(i2s->clk_ref);
 74
 75	return 0;
 76}
 77
 78static int img_i2s_out_resume(struct device *dev)
 79{
 80	struct img_i2s_out *i2s = dev_get_drvdata(dev);
 81	int ret;
 82
 83	if (!i2s->force_clk_active) {
 84		ret = clk_prepare_enable(i2s->clk_ref);
 85		if (ret) {
 86			dev_err(dev, "clk_enable failed: %d\n", ret);
 87			return ret;
 88		}
 
 
 
 
 
 89	}
 90
 91	return 0;
 92}
 93
 94static inline void img_i2s_out_writel(struct img_i2s_out *i2s, u32 val,
 95					u32 reg)
 96{
 97	writel(val, i2s->base + reg);
 98}
 99
100static inline u32 img_i2s_out_readl(struct img_i2s_out *i2s, u32 reg)
101{
102	return readl(i2s->base + reg);
103}
104
105static inline void img_i2s_out_ch_writel(struct img_i2s_out *i2s,
106					u32 chan, u32 val, u32 reg)
107{
108	writel(val, i2s->channel_base + (chan * IMG_I2S_OUT_CH_STRIDE) + reg);
109}
110
111static inline u32 img_i2s_out_ch_readl(struct img_i2s_out *i2s, u32 chan,
112					u32 reg)
113{
114	return readl(i2s->channel_base + (chan * IMG_I2S_OUT_CH_STRIDE) + reg);
115}
116
117static inline void img_i2s_out_ch_disable(struct img_i2s_out *i2s, u32 chan)
118{
119	u32 reg;
120
121	reg = img_i2s_out_ch_readl(i2s, chan, IMG_I2S_OUT_CH_CTL);
122	reg &= ~IMG_I2S_OUT_CHAN_CTL_ME_MASK;
123	img_i2s_out_ch_writel(i2s, chan, reg, IMG_I2S_OUT_CH_CTL);
124}
125
126static inline void img_i2s_out_ch_enable(struct img_i2s_out *i2s, u32 chan)
127{
128	u32 reg;
129
130	reg = img_i2s_out_ch_readl(i2s, chan, IMG_I2S_OUT_CH_CTL);
131	reg |= IMG_I2S_OUT_CHAN_CTL_ME_MASK;
132	img_i2s_out_ch_writel(i2s, chan, reg, IMG_I2S_OUT_CH_CTL);
133}
134
135static inline void img_i2s_out_disable(struct img_i2s_out *i2s)
136{
137	u32 reg;
138
139	reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
140	reg &= ~IMG_I2S_OUT_CTL_ME_MASK;
141	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
142}
143
144static inline void img_i2s_out_enable(struct img_i2s_out *i2s)
145{
146	u32 reg;
147
148	reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
149	reg |= IMG_I2S_OUT_CTL_ME_MASK;
150	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
151}
152
153static void img_i2s_out_reset(struct img_i2s_out *i2s)
154{
155	int i;
156	u32 core_ctl, chan_ctl;
157
158	core_ctl = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL) &
159			~IMG_I2S_OUT_CTL_ME_MASK &
160			~IMG_I2S_OUT_CTL_DATA_EN_MASK;
161
162	if (!i2s->force_clk_active)
163		core_ctl &= ~IMG_I2S_OUT_CTL_CLK_EN_MASK;
164
165	chan_ctl = img_i2s_out_ch_readl(i2s, 0, IMG_I2S_OUT_CH_CTL) &
166			~IMG_I2S_OUT_CHAN_CTL_ME_MASK;
167
168	reset_control_assert(i2s->rst);
169	reset_control_deassert(i2s->rst);
170
171	for (i = 0; i < i2s->max_i2s_chan; i++)
172		img_i2s_out_ch_writel(i2s, i, chan_ctl, IMG_I2S_OUT_CH_CTL);
173
174	for (i = 0; i < i2s->active_channels; i++)
175		img_i2s_out_ch_enable(i2s, i);
176
177	img_i2s_out_writel(i2s, core_ctl, IMG_I2S_OUT_CTL);
178	img_i2s_out_enable(i2s);
179}
180
181static int img_i2s_out_trigger(struct snd_pcm_substream *substream, int cmd,
182	struct snd_soc_dai *dai)
183{
184	struct img_i2s_out *i2s = snd_soc_dai_get_drvdata(dai);
185	u32 reg;
186
187	switch (cmd) {
188	case SNDRV_PCM_TRIGGER_START:
189	case SNDRV_PCM_TRIGGER_RESUME:
190	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
191		reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
192		if (!i2s->force_clk_active)
193			reg |= IMG_I2S_OUT_CTL_CLK_EN_MASK;
194		reg |= IMG_I2S_OUT_CTL_DATA_EN_MASK;
195		img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
196		break;
197	case SNDRV_PCM_TRIGGER_STOP:
198	case SNDRV_PCM_TRIGGER_SUSPEND:
199	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
200		img_i2s_out_reset(i2s);
201		break;
202	default:
203		return -EINVAL;
204	}
205
206	return 0;
207}
208
209static int img_i2s_out_hw_params(struct snd_pcm_substream *substream,
210	struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
211{
212	struct img_i2s_out *i2s = snd_soc_dai_get_drvdata(dai);
213	unsigned int channels, i2s_channels;
214	long pre_div_a, pre_div_b, diff_a, diff_b, rate, clk_rate;
215	int i;
216	u32 reg, control_mask, control_set = 0;
217	snd_pcm_format_t format;
218
219	rate = params_rate(params);
220	format = params_format(params);
221	channels = params_channels(params);
222	i2s_channels = channels / 2;
223
224	if (format != SNDRV_PCM_FORMAT_S32_LE)
225		return -EINVAL;
226
227	if ((channels < 2) ||
228	    (channels > (i2s->max_i2s_chan * 2)) ||
229	    (channels % 2))
230		return -EINVAL;
231
232	pre_div_a = clk_round_rate(i2s->clk_ref, rate * 256);
233	if (pre_div_a < 0)
234		return pre_div_a;
235	pre_div_b = clk_round_rate(i2s->clk_ref, rate * 384);
236	if (pre_div_b < 0)
237		return pre_div_b;
238
239	diff_a = abs((pre_div_a / 256) - rate);
240	diff_b = abs((pre_div_b / 384) - rate);
241
242	/* If diffs are equal, use lower clock rate */
243	if (diff_a > diff_b)
244		clk_set_rate(i2s->clk_ref, pre_div_b);
245	else
246		clk_set_rate(i2s->clk_ref, pre_div_a);
247
248	/*
249	 * Another driver (eg alsa machine driver) may have rejected the above
250	 * change. Get the current rate and set the register bit according to
251	 * the new minimum diff
252	 */
253	clk_rate = clk_get_rate(i2s->clk_ref);
254
255	diff_a = abs((clk_rate / 256) - rate);
256	diff_b = abs((clk_rate / 384) - rate);
257
258	if (diff_a > diff_b)
259		control_set |= IMG_I2S_OUT_CTL_CLK_MASK;
260
261	control_set |= ((i2s_channels - 1) <<
262		       IMG_I2S_OUT_CTL_ACTIVE_CHAN_SHIFT) &
263		       IMG_I2S_OUT_CTL_ACTIVE_CHAN_MASK;
264
265	control_mask = IMG_I2S_OUT_CTL_CLK_MASK |
266		       IMG_I2S_OUT_CTL_ACTIVE_CHAN_MASK;
267
268	img_i2s_out_disable(i2s);
269
270	reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
271	reg = (reg & ~control_mask) | control_set;
272	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
273
274	for (i = 0; i < i2s_channels; i++)
275		img_i2s_out_ch_enable(i2s, i);
276
277	for (; i < i2s->max_i2s_chan; i++)
278		img_i2s_out_ch_disable(i2s, i);
279
280	img_i2s_out_enable(i2s);
281
282	i2s->active_channels = i2s_channels;
283
284	return 0;
285}
286
287static int img_i2s_out_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
288{
289	struct img_i2s_out *i2s = snd_soc_dai_get_drvdata(dai);
290	int i;
291	bool force_clk_active;
292	u32 chan_control_mask, control_mask, chan_control_set = 0;
293	u32 reg, control_set = 0;
294
295	force_clk_active = ((fmt & SND_SOC_DAIFMT_CLOCK_MASK) ==
296			SND_SOC_DAIFMT_CONT);
297
298	if (force_clk_active)
299		control_set |= IMG_I2S_OUT_CTL_CLK_EN_MASK;
300
301	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
302	case SND_SOC_DAIFMT_CBM_CFM:
303		break;
304	case SND_SOC_DAIFMT_CBS_CFS:
305		control_set |= IMG_I2S_OUT_CTL_MASTER_MASK;
306		break;
307	default:
308		return -EINVAL;
309	}
310
311	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
312	case SND_SOC_DAIFMT_NB_NF:
313		control_set |= IMG_I2S_OUT_CTL_BCLK_POL_MASK;
314		break;
315	case SND_SOC_DAIFMT_NB_IF:
316		control_set |= IMG_I2S_OUT_CTL_BCLK_POL_MASK;
317		control_set |= IMG_I2S_OUT_CTL_FRM_CLK_POL_MASK;
318		break;
319	case SND_SOC_DAIFMT_IB_NF:
320		break;
321	case SND_SOC_DAIFMT_IB_IF:
322		control_set |= IMG_I2S_OUT_CTL_FRM_CLK_POL_MASK;
323		break;
324	default:
325		return -EINVAL;
326	}
327
328	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
329	case SND_SOC_DAIFMT_I2S:
330		chan_control_set |= IMG_I2S_OUT_CHAN_CTL_CLKT_MASK;
331		break;
332	case SND_SOC_DAIFMT_LEFT_J:
333		break;
334	default:
335		return -EINVAL;
336	}
337
338	control_mask = IMG_I2S_OUT_CTL_CLK_EN_MASK |
339		       IMG_I2S_OUT_CTL_MASTER_MASK |
340		       IMG_I2S_OUT_CTL_BCLK_POL_MASK |
341		       IMG_I2S_OUT_CTL_FRM_CLK_POL_MASK;
342
343	chan_control_mask = IMG_I2S_OUT_CHAN_CTL_CLKT_MASK;
344
 
 
 
 
345	img_i2s_out_disable(i2s);
346
347	reg = img_i2s_out_readl(i2s, IMG_I2S_OUT_CTL);
348	reg = (reg & ~control_mask) | control_set;
349	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
350
351	for (i = 0; i < i2s->active_channels; i++)
352		img_i2s_out_ch_disable(i2s, i);
353
354	for (i = 0; i < i2s->max_i2s_chan; i++) {
355		reg = img_i2s_out_ch_readl(i2s, i, IMG_I2S_OUT_CH_CTL);
356		reg = (reg & ~chan_control_mask) | chan_control_set;
357		img_i2s_out_ch_writel(i2s, i, reg, IMG_I2S_OUT_CH_CTL);
358	}
359
360	for (i = 0; i < i2s->active_channels; i++)
361		img_i2s_out_ch_enable(i2s, i);
362
363	img_i2s_out_enable(i2s);
 
364
365	i2s->force_clk_active = force_clk_active;
366
367	return 0;
368}
369
370static const struct snd_soc_dai_ops img_i2s_out_dai_ops = {
371	.trigger = img_i2s_out_trigger,
372	.hw_params = img_i2s_out_hw_params,
373	.set_fmt = img_i2s_out_set_fmt
374};
375
376static int img_i2s_out_dai_probe(struct snd_soc_dai *dai)
377{
378	struct img_i2s_out *i2s = snd_soc_dai_get_drvdata(dai);
379
380	snd_soc_dai_init_dma_data(dai, &i2s->dma_data, NULL);
381
382	return 0;
383}
384
385static const struct snd_soc_component_driver img_i2s_out_component = {
386	.name = "img-i2s-out"
 
387};
388
389static int img_i2s_out_dma_prepare_slave_config(struct snd_pcm_substream *st,
390	struct snd_pcm_hw_params *params, struct dma_slave_config *sc)
391{
392	unsigned int i2s_channels = params_channels(params) / 2;
393	struct snd_soc_pcm_runtime *rtd = st->private_data;
394	struct snd_dmaengine_dai_dma_data *dma_data;
395	int ret;
396
397	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, st);
398
399	ret = snd_hwparams_to_dma_slave_config(st, params, sc);
400	if (ret)
401		return ret;
402
403	sc->dst_addr = dma_data->addr;
404	sc->dst_addr_width = dma_data->addr_width;
405	sc->dst_maxburst = 4 * i2s_channels;
406
407	return 0;
408}
409
410static const struct snd_dmaengine_pcm_config img_i2s_out_dma_config = {
411	.prepare_slave_config = img_i2s_out_dma_prepare_slave_config
412};
413
414static int img_i2s_out_probe(struct platform_device *pdev)
415{
416	struct img_i2s_out *i2s;
417	struct resource *res;
418	void __iomem *base;
419	int i, ret;
420	unsigned int max_i2s_chan_pow_2;
421	u32 reg;
422	struct device *dev = &pdev->dev;
423
424	i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
425	if (!i2s)
426		return -ENOMEM;
427
428	platform_set_drvdata(pdev, i2s);
429
430	i2s->dev = &pdev->dev;
431
432	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
433	base = devm_ioremap_resource(&pdev->dev, res);
434	if (IS_ERR(base))
435		return PTR_ERR(base);
436
437	i2s->base = base;
438
439	if (of_property_read_u32(pdev->dev.of_node, "img,i2s-channels",
440			&i2s->max_i2s_chan)) {
441		dev_err(&pdev->dev, "No img,i2s-channels property\n");
442		return -EINVAL;
443	}
444
445	max_i2s_chan_pow_2 = 1 << get_count_order(i2s->max_i2s_chan);
446
447	i2s->channel_base = base + (max_i2s_chan_pow_2 * 0x20);
448
449	i2s->rst = devm_reset_control_get(&pdev->dev, "rst");
450	if (IS_ERR(i2s->rst)) {
451		if (PTR_ERR(i2s->rst) != -EPROBE_DEFER)
452			dev_err(&pdev->dev, "No top level reset found\n");
453		return PTR_ERR(i2s->rst);
454	}
455
456	i2s->clk_sys = devm_clk_get(&pdev->dev, "sys");
457	if (IS_ERR(i2s->clk_sys)) {
458		if (PTR_ERR(i2s->clk_sys) != -EPROBE_DEFER)
459			dev_err(dev, "Failed to acquire clock 'sys'\n");
460		return PTR_ERR(i2s->clk_sys);
461	}
462
463	i2s->clk_ref = devm_clk_get(&pdev->dev, "ref");
464	if (IS_ERR(i2s->clk_ref)) {
465		if (PTR_ERR(i2s->clk_ref) != -EPROBE_DEFER)
466			dev_err(dev, "Failed to acquire clock 'ref'\n");
467		return PTR_ERR(i2s->clk_ref);
 
 
 
 
 
 
 
 
 
 
468	}
469
470	ret = clk_prepare_enable(i2s->clk_sys);
471	if (ret)
472		return ret;
473
474	reg = IMG_I2S_OUT_CTL_FRM_SIZE_MASK;
475	img_i2s_out_writel(i2s, reg, IMG_I2S_OUT_CTL);
476
477	reg = IMG_I2S_OUT_CHAN_CTL_JUST_MASK |
478		IMG_I2S_OUT_CHAN_CTL_LT_MASK |
479		IMG_I2S_OUT_CHAN_CTL_CH_MASK |
480		(8 << IMG_I2S_OUT_CHAN_CTL_FMT_SHIFT);
481
482	for (i = 0; i < i2s->max_i2s_chan; i++)
483		img_i2s_out_ch_writel(i2s, i, reg, IMG_I2S_OUT_CH_CTL);
484
485	img_i2s_out_reset(i2s);
486
487	pm_runtime_enable(&pdev->dev);
488	if (!pm_runtime_enabled(&pdev->dev)) {
489		ret = img_i2s_out_resume(&pdev->dev);
490		if (ret)
491			goto err_pm_disable;
492	}
493
494	i2s->active_channels = 1;
495	i2s->dma_data.addr = res->start + IMG_I2S_OUT_TX_FIFO;
496	i2s->dma_data.addr_width = 4;
497	i2s->dma_data.maxburst = 4;
498
499	i2s->dai_driver.probe = img_i2s_out_dai_probe;
500	i2s->dai_driver.playback.channels_min = 2;
501	i2s->dai_driver.playback.channels_max = i2s->max_i2s_chan * 2;
502	i2s->dai_driver.playback.rates = SNDRV_PCM_RATE_8000_192000;
503	i2s->dai_driver.playback.formats = SNDRV_PCM_FMTBIT_S32_LE;
504	i2s->dai_driver.ops = &img_i2s_out_dai_ops;
505
506	ret = devm_snd_soc_register_component(&pdev->dev,
507			&img_i2s_out_component, &i2s->dai_driver, 1);
508	if (ret)
509		goto err_suspend;
510
511	ret = devm_snd_dmaengine_pcm_register(&pdev->dev,
512			&img_i2s_out_dma_config, 0);
513	if (ret)
514		goto err_suspend;
515
516	return 0;
517
518err_suspend:
519	if (!pm_runtime_status_suspended(&pdev->dev))
520		img_i2s_out_suspend(&pdev->dev);
521err_pm_disable:
522	pm_runtime_disable(&pdev->dev);
523	clk_disable_unprepare(i2s->clk_sys);
524
525	return ret;
526}
527
528static int img_i2s_out_dev_remove(struct platform_device *pdev)
529{
530	struct img_i2s_out *i2s = platform_get_drvdata(pdev);
531
532	pm_runtime_disable(&pdev->dev);
533	if (!pm_runtime_status_suspended(&pdev->dev))
534		img_i2s_out_suspend(&pdev->dev);
535
536	clk_disable_unprepare(i2s->clk_sys);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
537
538	return 0;
539}
 
540
541static const struct of_device_id img_i2s_out_of_match[] = {
542	{ .compatible = "img,i2s-out" },
543	{}
544};
545MODULE_DEVICE_TABLE(of, img_i2s_out_of_match);
546
547static const struct dev_pm_ops img_i2s_out_pm_ops = {
548	SET_RUNTIME_PM_OPS(img_i2s_out_suspend,
549			   img_i2s_out_resume, NULL)
 
550};
551
552static struct platform_driver img_i2s_out_driver = {
553	.driver = {
554		.name = "img-i2s-out",
555		.of_match_table = img_i2s_out_of_match,
556		.pm = &img_i2s_out_pm_ops
557	},
558	.probe = img_i2s_out_probe,
559	.remove = img_i2s_out_dev_remove
560};
561module_platform_driver(img_i2s_out_driver);
562
563MODULE_AUTHOR("Damien Horsley <Damien.Horsley@imgtec.com>");
564MODULE_DESCRIPTION("IMG I2S Output Driver");
565MODULE_LICENSE("GPL v2");