1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * tegra30_i2s.c - Tegra30 I2S driver
4 *
5 * Author: Stephen Warren <swarren@nvidia.com>
6 * Copyright (c) 2010-2012, NVIDIA CORPORATION. All rights reserved.
7 *
8 * Based on code copyright/by:
9 *
10 * Copyright (c) 2009-2010, NVIDIA Corporation.
11 * Scott Peterson <speterson@nvidia.com>
12 *
13 * Copyright (C) 2010 Google, Inc.
14 * Iliyan Malchev <malchev@google.com>
15 */
16
17#include <linux/clk.h>
18#include <linux/device.h>
19#include <linux/io.h>
20#include <linux/module.h>
21#include <linux/of.h>
22#include <linux/platform_device.h>
23#include <linux/pm_runtime.h>
24#include <linux/regmap.h>
25#include <linux/reset.h>
26#include <linux/slab.h>
27#include <sound/core.h>
28#include <sound/pcm.h>
29#include <sound/pcm_params.h>
30#include <sound/soc.h>
31#include <sound/dmaengine_pcm.h>
32
33#include "tegra30_ahub.h"
34#include "tegra30_i2s.h"
35
36#define DRV_NAME "tegra30-i2s"
37
38static __maybe_unused int tegra30_i2s_runtime_suspend(struct device *dev)
39{
40 struct tegra30_i2s *i2s = dev_get_drvdata(dev);
41
42 regcache_cache_only(map: i2s->regmap, enable: true);
43
44 clk_disable_unprepare(clk: i2s->clk_i2s);
45
46 return 0;
47}
48
49static __maybe_unused int tegra30_i2s_runtime_resume(struct device *dev)
50{
51 struct tegra30_i2s *i2s = dev_get_drvdata(dev);
52 int ret;
53
54 ret = clk_prepare_enable(clk: i2s->clk_i2s);
55 if (ret) {
56 dev_err(dev, "clk_enable failed: %d\n", ret);
57 return ret;
58 }
59
60 regcache_cache_only(map: i2s->regmap, enable: false);
61 regcache_mark_dirty(map: i2s->regmap);
62
63 ret = regcache_sync(map: i2s->regmap);
64 if (ret)
65 goto disable_clocks;
66
67 return 0;
68
69disable_clocks:
70 clk_disable_unprepare(clk: i2s->clk_i2s);
71
72 return ret;
73}
74
75static int tegra30_i2s_set_fmt(struct snd_soc_dai *dai,
76 unsigned int fmt)
77{
78 struct tegra30_i2s *i2s = snd_soc_dai_get_drvdata(dai);
79 unsigned int mask = 0, val = 0;
80
81 switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
82 case SND_SOC_DAIFMT_NB_NF:
83 break;
84 default:
85 return -EINVAL;
86 }
87
88 mask |= TEGRA30_I2S_CTRL_MASTER_ENABLE;
89 switch (fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
90 case SND_SOC_DAIFMT_BP_FP:
91 val |= TEGRA30_I2S_CTRL_MASTER_ENABLE;
92 break;
93 case SND_SOC_DAIFMT_BC_FC:
94 break;
95 default:
96 return -EINVAL;
97 }
98
99 mask |= TEGRA30_I2S_CTRL_FRAME_FORMAT_MASK |
100 TEGRA30_I2S_CTRL_LRCK_MASK;
101 switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
102 case SND_SOC_DAIFMT_DSP_A:
103 val |= TEGRA30_I2S_CTRL_FRAME_FORMAT_FSYNC;
104 val |= TEGRA30_I2S_CTRL_LRCK_L_LOW;
105 break;
106 case SND_SOC_DAIFMT_DSP_B:
107 val |= TEGRA30_I2S_CTRL_FRAME_FORMAT_FSYNC;
108 val |= TEGRA30_I2S_CTRL_LRCK_R_LOW;
109 break;
110 case SND_SOC_DAIFMT_I2S:
111 val |= TEGRA30_I2S_CTRL_FRAME_FORMAT_LRCK;
112 val |= TEGRA30_I2S_CTRL_LRCK_L_LOW;
113 break;
114 case SND_SOC_DAIFMT_RIGHT_J:
115 val |= TEGRA30_I2S_CTRL_FRAME_FORMAT_LRCK;
116 val |= TEGRA30_I2S_CTRL_LRCK_L_LOW;
117 break;
118 case SND_SOC_DAIFMT_LEFT_J:
119 val |= TEGRA30_I2S_CTRL_FRAME_FORMAT_LRCK;
120 val |= TEGRA30_I2S_CTRL_LRCK_L_LOW;
121 break;
122 default:
123 return -EINVAL;
124 }
125
126 pm_runtime_get_sync(dev: dai->dev);
127 regmap_update_bits(map: i2s->regmap, TEGRA30_I2S_CTRL, mask, val);
128 pm_runtime_put(dev: dai->dev);
129
130 return 0;
131}
132
133static int tegra30_i2s_hw_params(struct snd_pcm_substream *substream,
134 struct snd_pcm_hw_params *params,
135 struct snd_soc_dai *dai)
136{
137 struct device *dev = dai->dev;
138 struct tegra30_i2s *i2s = snd_soc_dai_get_drvdata(dai);
139 unsigned int mask, val, reg;
140 int ret, sample_size, srate, i2sclock, bitcnt;
141 struct tegra30_ahub_cif_conf cif_conf;
142
143 if (params_channels(p: params) != 2)
144 return -EINVAL;
145
146 mask = TEGRA30_I2S_CTRL_BIT_SIZE_MASK;
147 switch (params_format(p: params)) {
148 case SNDRV_PCM_FORMAT_S16_LE:
149 val = TEGRA30_I2S_CTRL_BIT_SIZE_16;
150 sample_size = 16;
151 break;
152 default:
153 return -EINVAL;
154 }
155
156 regmap_update_bits(map: i2s->regmap, TEGRA30_I2S_CTRL, mask, val);
157
158 srate = params_rate(p: params);
159
160 /* Final "* 2" required by Tegra hardware */
161 i2sclock = srate * params_channels(p: params) * sample_size * 2;
162
163 bitcnt = (i2sclock / (2 * srate)) - 1;
164 if (bitcnt < 0 || bitcnt > TEGRA30_I2S_TIMING_CHANNEL_BIT_COUNT_MASK_US)
165 return -EINVAL;
166
167 ret = clk_set_rate(clk: i2s->clk_i2s, rate: i2sclock);
168 if (ret) {
169 dev_err(dev, "Can't set I2S clock rate: %d\n", ret);
170 return ret;
171 }
172
173 val = bitcnt << TEGRA30_I2S_TIMING_CHANNEL_BIT_COUNT_SHIFT;
174
175 if (i2sclock % (2 * srate))
176 val |= TEGRA30_I2S_TIMING_NON_SYM_ENABLE;
177
178 regmap_write(map: i2s->regmap, TEGRA30_I2S_TIMING, val);
179
180 cif_conf.threshold = 0;
181 cif_conf.audio_channels = 2;
182 cif_conf.client_channels = 2;
183 cif_conf.audio_bits = TEGRA30_AUDIOCIF_BITS_16;
184 cif_conf.client_bits = TEGRA30_AUDIOCIF_BITS_16;
185 cif_conf.expand = 0;
186 cif_conf.stereo_conv = 0;
187 cif_conf.replicate = 0;
188 cif_conf.truncate = 0;
189 cif_conf.mono_conv = 0;
190
191 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
192 cif_conf.direction = TEGRA30_AUDIOCIF_DIRECTION_RX;
193 reg = TEGRA30_I2S_CIF_RX_CTRL;
194 } else {
195 cif_conf.direction = TEGRA30_AUDIOCIF_DIRECTION_TX;
196 reg = TEGRA30_I2S_CIF_TX_CTRL;
197 }
198
199 i2s->soc_data->set_audio_cif(i2s->regmap, reg, &cif_conf);
200
201 val = (1 << TEGRA30_I2S_OFFSET_RX_DATA_OFFSET_SHIFT) |
202 (1 << TEGRA30_I2S_OFFSET_TX_DATA_OFFSET_SHIFT);
203 regmap_write(map: i2s->regmap, TEGRA30_I2S_OFFSET, val);
204
205 return 0;
206}
207
208static void tegra30_i2s_start_playback(struct tegra30_i2s *i2s)
209{
210 tegra30_ahub_enable_tx_fifo(txcif: i2s->playback_fifo_cif);
211 regmap_update_bits(map: i2s->regmap, TEGRA30_I2S_CTRL,
212 TEGRA30_I2S_CTRL_XFER_EN_TX,
213 TEGRA30_I2S_CTRL_XFER_EN_TX);
214}
215
216static void tegra30_i2s_stop_playback(struct tegra30_i2s *i2s)
217{
218 tegra30_ahub_disable_tx_fifo(txcif: i2s->playback_fifo_cif);
219 regmap_update_bits(map: i2s->regmap, TEGRA30_I2S_CTRL,
220 TEGRA30_I2S_CTRL_XFER_EN_TX, val: 0);
221}
222
223static void tegra30_i2s_start_capture(struct tegra30_i2s *i2s)
224{
225 tegra30_ahub_enable_rx_fifo(rxcif: i2s->capture_fifo_cif);
226 regmap_update_bits(map: i2s->regmap, TEGRA30_I2S_CTRL,
227 TEGRA30_I2S_CTRL_XFER_EN_RX,
228 TEGRA30_I2S_CTRL_XFER_EN_RX);
229}
230
231static void tegra30_i2s_stop_capture(struct tegra30_i2s *i2s)
232{
233 regmap_update_bits(map: i2s->regmap, TEGRA30_I2S_CTRL,
234 TEGRA30_I2S_CTRL_XFER_EN_RX, val: 0);
235 tegra30_ahub_disable_rx_fifo(rxcif: i2s->capture_fifo_cif);
236}
237
238static int tegra30_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
239 struct snd_soc_dai *dai)
240{
241 struct tegra30_i2s *i2s = snd_soc_dai_get_drvdata(dai);
242
243 switch (cmd) {
244 case SNDRV_PCM_TRIGGER_START:
245 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
246 case SNDRV_PCM_TRIGGER_RESUME:
247 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
248 tegra30_i2s_start_playback(i2s);
249 else
250 tegra30_i2s_start_capture(i2s);
251 break;
252 case SNDRV_PCM_TRIGGER_STOP:
253 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
254 case SNDRV_PCM_TRIGGER_SUSPEND:
255 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
256 tegra30_i2s_stop_playback(i2s);
257 else
258 tegra30_i2s_stop_capture(i2s);
259 break;
260 default:
261 return -EINVAL;
262 }
263
264 return 0;
265}
266
267static int tegra30_i2s_set_tdm(struct snd_soc_dai *dai,
268 unsigned int tx_mask, unsigned int rx_mask,
269 int slots, int slot_width)
270{
271 struct tegra30_i2s *i2s = snd_soc_dai_get_drvdata(dai);
272 unsigned int mask, val;
273
274 dev_dbg(dai->dev, "%s: txmask=0x%08x rxmask=0x%08x slots=%d width=%d\n",
275 __func__, tx_mask, rx_mask, slots, slot_width);
276
277 mask = TEGRA30_I2S_SLOT_CTRL_TOTAL_SLOTS_MASK |
278 TEGRA30_I2S_SLOT_CTRL_RX_SLOT_ENABLES_MASK |
279 TEGRA30_I2S_SLOT_CTRL_TX_SLOT_ENABLES_MASK;
280
281 val = (tx_mask << TEGRA30_I2S_SLOT_CTRL_TX_SLOT_ENABLES_SHIFT) |
282 (rx_mask << TEGRA30_I2S_SLOT_CTRL_RX_SLOT_ENABLES_SHIFT) |
283 ((slots - 1) << TEGRA30_I2S_SLOT_CTRL_TOTAL_SLOTS_SHIFT);
284
285 pm_runtime_get_sync(dev: dai->dev);
286 regmap_update_bits(map: i2s->regmap, TEGRA30_I2S_SLOT_CTRL, mask, val);
287 /* set the fsync width to minimum of 1 clock width */
288 regmap_update_bits(map: i2s->regmap, TEGRA30_I2S_CH_CTRL,
289 TEGRA30_I2S_CH_CTRL_FSYNC_WIDTH_MASK, val: 0x0);
290 pm_runtime_put(dev: dai->dev);
291
292 return 0;
293}
294
295static int tegra30_i2s_probe(struct snd_soc_dai *dai)
296{
297 struct tegra30_i2s *i2s = snd_soc_dai_get_drvdata(dai);
298
299 snd_soc_dai_init_dma_data(dai, playback: &i2s->playback_dma_data,
300 capture: &i2s->capture_dma_data);
301
302 return 0;
303}
304
305static const struct snd_soc_dai_ops tegra30_i2s_dai_ops = {
306 .probe = tegra30_i2s_probe,
307 .set_fmt = tegra30_i2s_set_fmt,
308 .hw_params = tegra30_i2s_hw_params,
309 .trigger = tegra30_i2s_trigger,
310 .set_tdm_slot = tegra30_i2s_set_tdm,
311};
312
313static const struct snd_soc_dai_driver tegra30_i2s_dai_template = {
314 .playback = {
315 .stream_name = "Playback",
316 .channels_min = 2,
317 .channels_max = 2,
318 .rates = SNDRV_PCM_RATE_8000_96000,
319 .formats = SNDRV_PCM_FMTBIT_S16_LE,
320 },
321 .capture = {
322 .stream_name = "Capture",
323 .channels_min = 2,
324 .channels_max = 2,
325 .rates = SNDRV_PCM_RATE_8000_96000,
326 .formats = SNDRV_PCM_FMTBIT_S16_LE,
327 },
328 .ops = &tegra30_i2s_dai_ops,
329 .symmetric_rate = 1,
330};
331
332static const struct snd_soc_component_driver tegra30_i2s_component = {
333 .name = DRV_NAME,
334 .legacy_dai_naming = 1,
335};
336
337static bool tegra30_i2s_wr_rd_reg(struct device *dev, unsigned int reg)
338{
339 switch (reg) {
340 case TEGRA30_I2S_CTRL:
341 case TEGRA30_I2S_TIMING:
342 case TEGRA30_I2S_OFFSET:
343 case TEGRA30_I2S_CH_CTRL:
344 case TEGRA30_I2S_SLOT_CTRL:
345 case TEGRA30_I2S_CIF_RX_CTRL:
346 case TEGRA30_I2S_CIF_TX_CTRL:
347 case TEGRA30_I2S_FLOWCTL:
348 case TEGRA30_I2S_TX_STEP:
349 case TEGRA30_I2S_FLOW_STATUS:
350 case TEGRA30_I2S_FLOW_TOTAL:
351 case TEGRA30_I2S_FLOW_OVER:
352 case TEGRA30_I2S_FLOW_UNDER:
353 case TEGRA30_I2S_LCOEF_1_4_0:
354 case TEGRA30_I2S_LCOEF_1_4_1:
355 case TEGRA30_I2S_LCOEF_1_4_2:
356 case TEGRA30_I2S_LCOEF_1_4_3:
357 case TEGRA30_I2S_LCOEF_1_4_4:
358 case TEGRA30_I2S_LCOEF_1_4_5:
359 case TEGRA30_I2S_LCOEF_2_4_0:
360 case TEGRA30_I2S_LCOEF_2_4_1:
361 case TEGRA30_I2S_LCOEF_2_4_2:
362 return true;
363 default:
364 return false;
365 }
366}
367
368static bool tegra30_i2s_volatile_reg(struct device *dev, unsigned int reg)
369{
370 switch (reg) {
371 case TEGRA30_I2S_FLOW_STATUS:
372 case TEGRA30_I2S_FLOW_TOTAL:
373 case TEGRA30_I2S_FLOW_OVER:
374 case TEGRA30_I2S_FLOW_UNDER:
375 return true;
376 default:
377 return false;
378 }
379}
380
381static const struct regmap_config tegra30_i2s_regmap_config = {
382 .reg_bits = 32,
383 .reg_stride = 4,
384 .val_bits = 32,
385 .max_register = TEGRA30_I2S_LCOEF_2_4_2,
386 .writeable_reg = tegra30_i2s_wr_rd_reg,
387 .readable_reg = tegra30_i2s_wr_rd_reg,
388 .volatile_reg = tegra30_i2s_volatile_reg,
389 .cache_type = REGCACHE_FLAT,
390};
391
392static const struct tegra30_i2s_soc_data tegra30_i2s_config = {
393 .set_audio_cif = tegra30_ahub_set_cif,
394};
395
396static const struct tegra30_i2s_soc_data tegra124_i2s_config = {
397 .set_audio_cif = tegra124_ahub_set_cif,
398};
399
400static const struct of_device_id tegra30_i2s_of_match[] = {
401 { .compatible = "nvidia,tegra124-i2s", .data = &tegra124_i2s_config },
402 { .compatible = "nvidia,tegra30-i2s", .data = &tegra30_i2s_config },
403 {},
404};
405
406static int tegra30_i2s_platform_probe(struct platform_device *pdev)
407{
408 struct tegra30_i2s *i2s;
409 const struct tegra30_i2s_soc_data *soc_data;
410 u32 cif_ids[2];
411 void __iomem *regs;
412 int ret;
413
414 i2s = devm_kzalloc(dev: &pdev->dev, size: sizeof(struct tegra30_i2s), GFP_KERNEL);
415 if (!i2s) {
416 ret = -ENOMEM;
417 goto err;
418 }
419 dev_set_drvdata(dev: &pdev->dev, data: i2s);
420
421 soc_data = of_device_get_match_data(dev: &pdev->dev);
422 if (!soc_data) {
423 dev_err(&pdev->dev, "Error: No device match found\n");
424 ret = -ENODEV;
425 goto err;
426 }
427 i2s->soc_data = soc_data;
428
429 i2s->dai = tegra30_i2s_dai_template;
430 i2s->dai.name = dev_name(dev: &pdev->dev);
431
432 ret = of_property_read_u32_array(np: pdev->dev.of_node,
433 propname: "nvidia,ahub-cif-ids", out_values: cif_ids,
434 ARRAY_SIZE(cif_ids));
435 if (ret < 0)
436 goto err;
437
438 i2s->playback_i2s_cif = cif_ids[0];
439 i2s->capture_i2s_cif = cif_ids[1];
440
441 i2s->clk_i2s = devm_clk_get(dev: &pdev->dev, NULL);
442 if (IS_ERR(ptr: i2s->clk_i2s)) {
443 dev_err(&pdev->dev, "Can't retrieve i2s clock\n");
444 ret = PTR_ERR(ptr: i2s->clk_i2s);
445 goto err;
446 }
447
448 regs = devm_platform_ioremap_resource(pdev, index: 0);
449 if (IS_ERR(ptr: regs)) {
450 ret = PTR_ERR(ptr: regs);
451 goto err;
452 }
453
454 i2s->regmap = devm_regmap_init_mmio(&pdev->dev, regs,
455 &tegra30_i2s_regmap_config);
456 if (IS_ERR(ptr: i2s->regmap)) {
457 dev_err(&pdev->dev, "regmap init failed\n");
458 ret = PTR_ERR(ptr: i2s->regmap);
459 goto err;
460 }
461 regcache_cache_only(map: i2s->regmap, enable: true);
462
463 pm_runtime_enable(dev: &pdev->dev);
464
465 i2s->playback_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
466 i2s->playback_dma_data.maxburst = 4;
467 ret = tegra30_ahub_allocate_tx_fifo(txcif: &i2s->playback_fifo_cif,
468 dmachan: i2s->playback_dma_chan,
469 dmachan_len: sizeof(i2s->playback_dma_chan),
470 fiforeg: &i2s->playback_dma_data.addr);
471 if (ret) {
472 dev_err(&pdev->dev, "Could not alloc TX FIFO: %d\n", ret);
473 goto err_pm_disable;
474 }
475 ret = tegra30_ahub_set_rx_cif_source(rxcif: i2s->playback_i2s_cif,
476 txcif: i2s->playback_fifo_cif);
477 if (ret) {
478 dev_err(&pdev->dev, "Could not route TX FIFO: %d\n", ret);
479 goto err_free_tx_fifo;
480 }
481
482 i2s->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
483 i2s->capture_dma_data.maxburst = 4;
484 ret = tegra30_ahub_allocate_rx_fifo(rxcif: &i2s->capture_fifo_cif,
485 dmachan: i2s->capture_dma_chan,
486 dmachan_len: sizeof(i2s->capture_dma_chan),
487 fiforeg: &i2s->capture_dma_data.addr);
488 if (ret) {
489 dev_err(&pdev->dev, "Could not alloc RX FIFO: %d\n", ret);
490 goto err_unroute_tx_fifo;
491 }
492 ret = tegra30_ahub_set_rx_cif_source(rxcif: i2s->capture_fifo_cif,
493 txcif: i2s->capture_i2s_cif);
494 if (ret) {
495 dev_err(&pdev->dev, "Could not route TX FIFO: %d\n", ret);
496 goto err_free_rx_fifo;
497 }
498
499 ret = snd_soc_register_component(dev: &pdev->dev, component_driver: &tegra30_i2s_component,
500 dai_drv: &i2s->dai, num_dai: 1);
501 if (ret) {
502 dev_err(&pdev->dev, "Could not register DAI: %d\n", ret);
503 ret = -ENOMEM;
504 goto err_unroute_rx_fifo;
505 }
506
507 ret = tegra_pcm_platform_register_with_chan_names(dev: &pdev->dev,
508 config: &i2s->dma_config, txdmachan: i2s->playback_dma_chan,
509 rxdmachan: i2s->capture_dma_chan);
510 if (ret) {
511 dev_err(&pdev->dev, "Could not register PCM: %d\n", ret);
512 goto err_unregister_component;
513 }
514
515 return 0;
516
517err_unregister_component:
518 snd_soc_unregister_component(dev: &pdev->dev);
519err_unroute_rx_fifo:
520 tegra30_ahub_unset_rx_cif_source(rxcif: i2s->capture_fifo_cif);
521err_free_rx_fifo:
522 tegra30_ahub_free_rx_fifo(rxcif: i2s->capture_fifo_cif);
523err_unroute_tx_fifo:
524 tegra30_ahub_unset_rx_cif_source(rxcif: i2s->playback_i2s_cif);
525err_free_tx_fifo:
526 tegra30_ahub_free_tx_fifo(txcif: i2s->playback_fifo_cif);
527err_pm_disable:
528 pm_runtime_disable(dev: &pdev->dev);
529err:
530 return ret;
531}
532
533static void tegra30_i2s_platform_remove(struct platform_device *pdev)
534{
535 struct tegra30_i2s *i2s = dev_get_drvdata(dev: &pdev->dev);
536
537 tegra_pcm_platform_unregister(dev: &pdev->dev);
538 snd_soc_unregister_component(dev: &pdev->dev);
539
540 tegra30_ahub_unset_rx_cif_source(rxcif: i2s->capture_fifo_cif);
541 tegra30_ahub_free_rx_fifo(rxcif: i2s->capture_fifo_cif);
542
543 tegra30_ahub_unset_rx_cif_source(rxcif: i2s->playback_i2s_cif);
544 tegra30_ahub_free_tx_fifo(txcif: i2s->playback_fifo_cif);
545
546 pm_runtime_disable(dev: &pdev->dev);
547}
548
549static const struct dev_pm_ops tegra30_i2s_pm_ops = {
550 SET_RUNTIME_PM_OPS(tegra30_i2s_runtime_suspend,
551 tegra30_i2s_runtime_resume, NULL)
552 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
553 pm_runtime_force_resume)
554};
555
556static struct platform_driver tegra30_i2s_driver = {
557 .driver = {
558 .name = DRV_NAME,
559 .of_match_table = tegra30_i2s_of_match,
560 .pm = &tegra30_i2s_pm_ops,
561 },
562 .probe = tegra30_i2s_platform_probe,
563 .remove_new = tegra30_i2s_platform_remove,
564};
565module_platform_driver(tegra30_i2s_driver);
566
567MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
568MODULE_DESCRIPTION("Tegra30 I2S ASoC driver");
569MODULE_LICENSE("GPL");
570MODULE_ALIAS("platform:" DRV_NAME);
571MODULE_DEVICE_TABLE(of, tegra30_i2s_of_match);
572

source code of linux/sound/soc/tegra/tegra30_i2s.c