xref: /linux/drivers/gpu/drm/msm/dp/dp_audio.c (revision c156ef573efe4230ef3dc1ff2ec0038fe0eb217f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2016-2020, The Linux Foundation. All rights reserved.
4  */
5 
6 
7 #define pr_fmt(fmt)	"[drm-dp] %s: " fmt, __func__
8 
9 #include <linux/platform_device.h>
10 
11 #include <drm/display/drm_dp_helper.h>
12 #include <drm/drm_edid.h>
13 
14 #include "dp_catalog.h"
15 #include "dp_audio.h"
16 #include "dp_panel.h"
17 #include "dp_display.h"
18 #include "dp_utils.h"
19 
20 struct msm_dp_audio_private {
21 	struct platform_device *audio_pdev;
22 	struct platform_device *pdev;
23 	struct drm_device *drm_dev;
24 	struct msm_dp_catalog *catalog;
25 
26 	u32 channels;
27 
28 	struct msm_dp_audio msm_dp_audio;
29 };
30 
31 static u32 msm_dp_audio_get_header(struct msm_dp_catalog *catalog,
32 		enum msm_dp_catalog_audio_sdp_type sdp,
33 		enum msm_dp_catalog_audio_header_type header)
34 {
35 	return msm_dp_catalog_audio_get_header(catalog, sdp, header);
36 }
37 
38 static void msm_dp_audio_set_header(struct msm_dp_catalog *catalog,
39 		u32 data,
40 		enum msm_dp_catalog_audio_sdp_type sdp,
41 		enum msm_dp_catalog_audio_header_type header)
42 {
43 	msm_dp_catalog_audio_set_header(catalog, sdp, header, data);
44 }
45 
46 static void msm_dp_audio_stream_sdp(struct msm_dp_audio_private *audio)
47 {
48 	struct msm_dp_catalog *catalog = audio->catalog;
49 	u32 value, new_value;
50 	u8 parity_byte;
51 
52 	/* Config header and parity byte 1 */
53 	value = msm_dp_audio_get_header(catalog,
54 			DP_AUDIO_SDP_STREAM, DP_AUDIO_SDP_HEADER_1);
55 
56 	new_value = 0x02;
57 	parity_byte = msm_dp_utils_calculate_parity(new_value);
58 	value |= ((new_value << HEADER_BYTE_1_BIT)
59 			| (parity_byte << PARITY_BYTE_1_BIT));
60 	drm_dbg_dp(audio->drm_dev,
61 			"Header Byte 1: value = 0x%x, parity_byte = 0x%x\n",
62 			value, parity_byte);
63 	msm_dp_audio_set_header(catalog, value,
64 		DP_AUDIO_SDP_STREAM, DP_AUDIO_SDP_HEADER_1);
65 
66 	/* Config header and parity byte 2 */
67 	value = msm_dp_audio_get_header(catalog,
68 			DP_AUDIO_SDP_STREAM, DP_AUDIO_SDP_HEADER_2);
69 	new_value = value;
70 	parity_byte = msm_dp_utils_calculate_parity(new_value);
71 	value |= ((new_value << HEADER_BYTE_2_BIT)
72 			| (parity_byte << PARITY_BYTE_2_BIT));
73 	drm_dbg_dp(audio->drm_dev,
74 			"Header Byte 2: value = 0x%x, parity_byte = 0x%x\n",
75 			value, parity_byte);
76 
77 	msm_dp_audio_set_header(catalog, value,
78 		DP_AUDIO_SDP_STREAM, DP_AUDIO_SDP_HEADER_2);
79 
80 	/* Config header and parity byte 3 */
81 	value = msm_dp_audio_get_header(catalog,
82 			DP_AUDIO_SDP_STREAM, DP_AUDIO_SDP_HEADER_3);
83 
84 	new_value = audio->channels - 1;
85 	parity_byte = msm_dp_utils_calculate_parity(new_value);
86 	value |= ((new_value << HEADER_BYTE_3_BIT)
87 			| (parity_byte << PARITY_BYTE_3_BIT));
88 	drm_dbg_dp(audio->drm_dev,
89 			"Header Byte 3: value = 0x%x, parity_byte = 0x%x\n",
90 		value, parity_byte);
91 
92 	msm_dp_audio_set_header(catalog, value,
93 		DP_AUDIO_SDP_STREAM, DP_AUDIO_SDP_HEADER_3);
94 }
95 
96 static void msm_dp_audio_timestamp_sdp(struct msm_dp_audio_private *audio)
97 {
98 	struct msm_dp_catalog *catalog = audio->catalog;
99 	u32 value, new_value;
100 	u8 parity_byte;
101 
102 	/* Config header and parity byte 1 */
103 	value = msm_dp_audio_get_header(catalog,
104 			DP_AUDIO_SDP_TIMESTAMP, DP_AUDIO_SDP_HEADER_1);
105 
106 	new_value = 0x1;
107 	parity_byte = msm_dp_utils_calculate_parity(new_value);
108 	value |= ((new_value << HEADER_BYTE_1_BIT)
109 			| (parity_byte << PARITY_BYTE_1_BIT));
110 	drm_dbg_dp(audio->drm_dev,
111 			"Header Byte 1: value = 0x%x, parity_byte = 0x%x\n",
112 			value, parity_byte);
113 	msm_dp_audio_set_header(catalog, value,
114 		DP_AUDIO_SDP_TIMESTAMP, DP_AUDIO_SDP_HEADER_1);
115 
116 	/* Config header and parity byte 2 */
117 	value = msm_dp_audio_get_header(catalog,
118 			DP_AUDIO_SDP_TIMESTAMP, DP_AUDIO_SDP_HEADER_2);
119 
120 	new_value = 0x17;
121 	parity_byte = msm_dp_utils_calculate_parity(new_value);
122 	value |= ((new_value << HEADER_BYTE_2_BIT)
123 			| (parity_byte << PARITY_BYTE_2_BIT));
124 	drm_dbg_dp(audio->drm_dev,
125 			"Header Byte 2: value = 0x%x, parity_byte = 0x%x\n",
126 			value, parity_byte);
127 	msm_dp_audio_set_header(catalog, value,
128 		DP_AUDIO_SDP_TIMESTAMP, DP_AUDIO_SDP_HEADER_2);
129 
130 	/* Config header and parity byte 3 */
131 	value = msm_dp_audio_get_header(catalog,
132 			DP_AUDIO_SDP_TIMESTAMP, DP_AUDIO_SDP_HEADER_3);
133 
134 	new_value = (0x0 | (0x11 << 2));
135 	parity_byte = msm_dp_utils_calculate_parity(new_value);
136 	value |= ((new_value << HEADER_BYTE_3_BIT)
137 			| (parity_byte << PARITY_BYTE_3_BIT));
138 	drm_dbg_dp(audio->drm_dev,
139 			"Header Byte 3: value = 0x%x, parity_byte = 0x%x\n",
140 			value, parity_byte);
141 	msm_dp_audio_set_header(catalog, value,
142 		DP_AUDIO_SDP_TIMESTAMP, DP_AUDIO_SDP_HEADER_3);
143 }
144 
145 static void msm_dp_audio_infoframe_sdp(struct msm_dp_audio_private *audio)
146 {
147 	struct msm_dp_catalog *catalog = audio->catalog;
148 	u32 value, new_value;
149 	u8 parity_byte;
150 
151 	/* Config header and parity byte 1 */
152 	value = msm_dp_audio_get_header(catalog,
153 			DP_AUDIO_SDP_INFOFRAME, DP_AUDIO_SDP_HEADER_1);
154 
155 	new_value = 0x84;
156 	parity_byte = msm_dp_utils_calculate_parity(new_value);
157 	value |= ((new_value << HEADER_BYTE_1_BIT)
158 			| (parity_byte << PARITY_BYTE_1_BIT));
159 	drm_dbg_dp(audio->drm_dev,
160 			"Header Byte 1: value = 0x%x, parity_byte = 0x%x\n",
161 			value, parity_byte);
162 	msm_dp_audio_set_header(catalog, value,
163 		DP_AUDIO_SDP_INFOFRAME, DP_AUDIO_SDP_HEADER_1);
164 
165 	/* Config header and parity byte 2 */
166 	value = msm_dp_audio_get_header(catalog,
167 			DP_AUDIO_SDP_INFOFRAME, DP_AUDIO_SDP_HEADER_2);
168 
169 	new_value = 0x1b;
170 	parity_byte = msm_dp_utils_calculate_parity(new_value);
171 	value |= ((new_value << HEADER_BYTE_2_BIT)
172 			| (parity_byte << PARITY_BYTE_2_BIT));
173 	drm_dbg_dp(audio->drm_dev,
174 			"Header Byte 2: value = 0x%x, parity_byte = 0x%x\n",
175 			value, parity_byte);
176 	msm_dp_audio_set_header(catalog, value,
177 		DP_AUDIO_SDP_INFOFRAME, DP_AUDIO_SDP_HEADER_2);
178 
179 	/* Config header and parity byte 3 */
180 	value = msm_dp_audio_get_header(catalog,
181 			DP_AUDIO_SDP_INFOFRAME, DP_AUDIO_SDP_HEADER_3);
182 
183 	new_value = (0x0 | (0x11 << 2));
184 	parity_byte = msm_dp_utils_calculate_parity(new_value);
185 	value |= ((new_value << HEADER_BYTE_3_BIT)
186 			| (parity_byte << PARITY_BYTE_3_BIT));
187 	drm_dbg_dp(audio->drm_dev,
188 			"Header Byte 3: value = 0x%x, parity_byte = 0x%x\n",
189 			new_value, parity_byte);
190 	msm_dp_audio_set_header(catalog, value,
191 		DP_AUDIO_SDP_INFOFRAME, DP_AUDIO_SDP_HEADER_3);
192 }
193 
194 static void msm_dp_audio_copy_management_sdp(struct msm_dp_audio_private *audio)
195 {
196 	struct msm_dp_catalog *catalog = audio->catalog;
197 	u32 value, new_value;
198 	u8 parity_byte;
199 
200 	/* Config header and parity byte 1 */
201 	value = msm_dp_audio_get_header(catalog,
202 			DP_AUDIO_SDP_COPYMANAGEMENT, DP_AUDIO_SDP_HEADER_1);
203 
204 	new_value = 0x05;
205 	parity_byte = msm_dp_utils_calculate_parity(new_value);
206 	value |= ((new_value << HEADER_BYTE_1_BIT)
207 			| (parity_byte << PARITY_BYTE_1_BIT));
208 	drm_dbg_dp(audio->drm_dev,
209 			"Header Byte 1: value = 0x%x, parity_byte = 0x%x\n",
210 			value, parity_byte);
211 	msm_dp_audio_set_header(catalog, value,
212 		DP_AUDIO_SDP_COPYMANAGEMENT, DP_AUDIO_SDP_HEADER_1);
213 
214 	/* Config header and parity byte 2 */
215 	value = msm_dp_audio_get_header(catalog,
216 			DP_AUDIO_SDP_COPYMANAGEMENT, DP_AUDIO_SDP_HEADER_2);
217 
218 	new_value = 0x0F;
219 	parity_byte = msm_dp_utils_calculate_parity(new_value);
220 	value |= ((new_value << HEADER_BYTE_2_BIT)
221 			| (parity_byte << PARITY_BYTE_2_BIT));
222 	drm_dbg_dp(audio->drm_dev,
223 			"Header Byte 2: value = 0x%x, parity_byte = 0x%x\n",
224 			value, parity_byte);
225 	msm_dp_audio_set_header(catalog, value,
226 		DP_AUDIO_SDP_COPYMANAGEMENT, DP_AUDIO_SDP_HEADER_2);
227 
228 	/* Config header and parity byte 3 */
229 	value = msm_dp_audio_get_header(catalog,
230 			DP_AUDIO_SDP_COPYMANAGEMENT, DP_AUDIO_SDP_HEADER_3);
231 
232 	new_value = 0x0;
233 	parity_byte = msm_dp_utils_calculate_parity(new_value);
234 	value |= ((new_value << HEADER_BYTE_3_BIT)
235 			| (parity_byte << PARITY_BYTE_3_BIT));
236 	drm_dbg_dp(audio->drm_dev,
237 			"Header Byte 3: value = 0x%x, parity_byte = 0x%x\n",
238 			value, parity_byte);
239 	msm_dp_audio_set_header(catalog, value,
240 		DP_AUDIO_SDP_COPYMANAGEMENT, DP_AUDIO_SDP_HEADER_3);
241 }
242 
243 static void msm_dp_audio_isrc_sdp(struct msm_dp_audio_private *audio)
244 {
245 	struct msm_dp_catalog *catalog = audio->catalog;
246 	u32 value, new_value;
247 	u8 parity_byte;
248 
249 	/* Config header and parity byte 1 */
250 	value = msm_dp_audio_get_header(catalog,
251 			DP_AUDIO_SDP_ISRC, DP_AUDIO_SDP_HEADER_1);
252 
253 	new_value = 0x06;
254 	parity_byte = msm_dp_utils_calculate_parity(new_value);
255 	value |= ((new_value << HEADER_BYTE_1_BIT)
256 			| (parity_byte << PARITY_BYTE_1_BIT));
257 	drm_dbg_dp(audio->drm_dev,
258 			"Header Byte 1: value = 0x%x, parity_byte = 0x%x\n",
259 			value, parity_byte);
260 	msm_dp_audio_set_header(catalog, value,
261 		DP_AUDIO_SDP_ISRC, DP_AUDIO_SDP_HEADER_1);
262 
263 	/* Config header and parity byte 2 */
264 	value = msm_dp_audio_get_header(catalog,
265 			DP_AUDIO_SDP_ISRC, DP_AUDIO_SDP_HEADER_2);
266 
267 	new_value = 0x0F;
268 	parity_byte = msm_dp_utils_calculate_parity(new_value);
269 	value |= ((new_value << HEADER_BYTE_2_BIT)
270 			| (parity_byte << PARITY_BYTE_2_BIT));
271 	drm_dbg_dp(audio->drm_dev,
272 			"Header Byte 2: value = 0x%x, parity_byte = 0x%x\n",
273 			value, parity_byte);
274 	msm_dp_audio_set_header(catalog, value,
275 		DP_AUDIO_SDP_ISRC, DP_AUDIO_SDP_HEADER_2);
276 }
277 
278 static void msm_dp_audio_setup_sdp(struct msm_dp_audio_private *audio)
279 {
280 	msm_dp_catalog_audio_config_sdp(audio->catalog);
281 
282 	msm_dp_audio_stream_sdp(audio);
283 	msm_dp_audio_timestamp_sdp(audio);
284 	msm_dp_audio_infoframe_sdp(audio);
285 	msm_dp_audio_copy_management_sdp(audio);
286 	msm_dp_audio_isrc_sdp(audio);
287 }
288 
289 static void msm_dp_audio_setup_acr(struct msm_dp_audio_private *audio)
290 {
291 	u32 select = 0;
292 	struct msm_dp_catalog *catalog = audio->catalog;
293 
294 	switch (audio->msm_dp_audio.bw_code) {
295 	case DP_LINK_BW_1_62:
296 		select = 0;
297 		break;
298 	case DP_LINK_BW_2_7:
299 		select = 1;
300 		break;
301 	case DP_LINK_BW_5_4:
302 		select = 2;
303 		break;
304 	case DP_LINK_BW_8_1:
305 		select = 3;
306 		break;
307 	default:
308 		drm_dbg_dp(audio->drm_dev, "Unknown link rate\n");
309 		select = 0;
310 		break;
311 	}
312 
313 	msm_dp_catalog_audio_config_acr(catalog, select);
314 }
315 
316 static void msm_dp_audio_safe_to_exit_level(struct msm_dp_audio_private *audio)
317 {
318 	struct msm_dp_catalog *catalog = audio->catalog;
319 	u32 safe_to_exit_level = 0;
320 
321 	switch (audio->msm_dp_audio.lane_count) {
322 	case 1:
323 		safe_to_exit_level = 14;
324 		break;
325 	case 2:
326 		safe_to_exit_level = 8;
327 		break;
328 	case 4:
329 		safe_to_exit_level = 5;
330 		break;
331 	default:
332 		drm_dbg_dp(audio->drm_dev,
333 				"setting the default safe_to_exit_level = %u\n",
334 				safe_to_exit_level);
335 		safe_to_exit_level = 14;
336 		break;
337 	}
338 
339 	msm_dp_catalog_audio_sfe_level(catalog, safe_to_exit_level);
340 }
341 
342 static void msm_dp_audio_enable(struct msm_dp_audio_private *audio, bool enable)
343 {
344 	struct msm_dp_catalog *catalog = audio->catalog;
345 
346 	msm_dp_catalog_audio_enable(catalog, enable);
347 }
348 
349 static struct msm_dp_audio_private *msm_dp_audio_get_data(struct platform_device *pdev)
350 {
351 	struct msm_dp_audio *msm_dp_audio;
352 	struct msm_dp *msm_dp_display;
353 
354 	if (!pdev) {
355 		DRM_ERROR("invalid input\n");
356 		return ERR_PTR(-ENODEV);
357 	}
358 
359 	msm_dp_display = platform_get_drvdata(pdev);
360 	if (!msm_dp_display) {
361 		DRM_ERROR("invalid input\n");
362 		return ERR_PTR(-ENODEV);
363 	}
364 
365 	msm_dp_audio = msm_dp_display->msm_dp_audio;
366 
367 	if (!msm_dp_audio) {
368 		DRM_ERROR("invalid msm_dp_audio data\n");
369 		return ERR_PTR(-EINVAL);
370 	}
371 
372 	return container_of(msm_dp_audio, struct msm_dp_audio_private, msm_dp_audio);
373 }
374 
375 static int msm_dp_audio_hook_plugged_cb(struct device *dev, void *data,
376 		hdmi_codec_plugged_cb fn,
377 		struct device *codec_dev)
378 {
379 
380 	struct platform_device *pdev;
381 	struct msm_dp *msm_dp_display;
382 
383 	pdev = to_platform_device(dev);
384 	if (!pdev) {
385 		pr_err("invalid input\n");
386 		return -ENODEV;
387 	}
388 
389 	msm_dp_display = platform_get_drvdata(pdev);
390 	if (!msm_dp_display) {
391 		pr_err("invalid input\n");
392 		return -ENODEV;
393 	}
394 
395 	return msm_dp_display_set_plugged_cb(msm_dp_display, fn, codec_dev);
396 }
397 
398 static int msm_dp_audio_get_eld(struct device *dev,
399 	void *data, uint8_t *buf, size_t len)
400 {
401 	struct platform_device *pdev;
402 	struct msm_dp *msm_dp_display;
403 
404 	pdev = to_platform_device(dev);
405 
406 	if (!pdev) {
407 		DRM_ERROR("invalid input\n");
408 		return -ENODEV;
409 	}
410 
411 	msm_dp_display = platform_get_drvdata(pdev);
412 	if (!msm_dp_display) {
413 		DRM_ERROR("invalid input\n");
414 		return -ENODEV;
415 	}
416 
417 	mutex_lock(&msm_dp_display->connector->eld_mutex);
418 	memcpy(buf, msm_dp_display->connector->eld,
419 		min(sizeof(msm_dp_display->connector->eld), len));
420 	mutex_unlock(&msm_dp_display->connector->eld_mutex);
421 
422 	return 0;
423 }
424 
425 int msm_dp_audio_hw_params(struct device *dev,
426 	void *data,
427 	struct hdmi_codec_daifmt *daifmt,
428 	struct hdmi_codec_params *params)
429 {
430 	int rc = 0;
431 	struct msm_dp_audio_private *audio;
432 	struct platform_device *pdev;
433 	struct msm_dp *msm_dp_display;
434 
435 	pdev = to_platform_device(dev);
436 	msm_dp_display = platform_get_drvdata(pdev);
437 
438 	/*
439 	 * there could be cases where sound card can be opened even
440 	 * before OR even when DP is not connected . This can cause
441 	 * unclocked access as the audio subsystem relies on the DP
442 	 * driver to maintain the correct state of clocks. To protect
443 	 * such cases check for connection status and bail out if not
444 	 * connected.
445 	 */
446 	if (!msm_dp_display->power_on) {
447 		rc = -EINVAL;
448 		goto end;
449 	}
450 
451 	audio = msm_dp_audio_get_data(pdev);
452 	if (IS_ERR(audio)) {
453 		rc = PTR_ERR(audio);
454 		goto end;
455 	}
456 
457 	audio->channels = params->channels;
458 
459 	msm_dp_audio_setup_sdp(audio);
460 	msm_dp_audio_setup_acr(audio);
461 	msm_dp_audio_safe_to_exit_level(audio);
462 	msm_dp_audio_enable(audio, true);
463 	msm_dp_display_signal_audio_start(msm_dp_display);
464 	msm_dp_display->audio_enabled = true;
465 
466 end:
467 	return rc;
468 }
469 
470 static void msm_dp_audio_shutdown(struct device *dev, void *data)
471 {
472 	struct msm_dp_audio_private *audio;
473 	struct platform_device *pdev;
474 	struct msm_dp *msm_dp_display;
475 
476 	pdev = to_platform_device(dev);
477 	msm_dp_display = platform_get_drvdata(pdev);
478 	audio = msm_dp_audio_get_data(pdev);
479 	if (IS_ERR(audio)) {
480 		DRM_ERROR("failed to get audio data\n");
481 		return;
482 	}
483 
484 	/*
485 	 * if audio was not enabled there is no need
486 	 * to execute the shutdown and we can bail out early.
487 	 * This also makes sure that we dont cause an unclocked
488 	 * access when audio subsystem calls this without DP being
489 	 * connected. is_connected cannot be used here as its set
490 	 * to false earlier than this call
491 	 */
492 	if (!msm_dp_display->audio_enabled)
493 		return;
494 
495 	msm_dp_audio_enable(audio, false);
496 	/* signal the dp display to safely shutdown clocks */
497 	msm_dp_display_signal_audio_complete(msm_dp_display);
498 }
499 
500 static const struct hdmi_codec_ops msm_dp_audio_codec_ops = {
501 	.hw_params = msm_dp_audio_hw_params,
502 	.audio_shutdown = msm_dp_audio_shutdown,
503 	.get_eld = msm_dp_audio_get_eld,
504 	.hook_plugged_cb = msm_dp_audio_hook_plugged_cb,
505 };
506 
507 static struct hdmi_codec_pdata codec_data = {
508 	.ops = &msm_dp_audio_codec_ops,
509 	.max_i2s_channels = 8,
510 	.i2s = 1,
511 };
512 
513 void msm_dp_unregister_audio_driver(struct device *dev, struct msm_dp_audio *msm_dp_audio)
514 {
515 	struct msm_dp_audio_private *audio_priv;
516 
517 	audio_priv = container_of(msm_dp_audio, struct msm_dp_audio_private, msm_dp_audio);
518 
519 	if (audio_priv->audio_pdev) {
520 		platform_device_unregister(audio_priv->audio_pdev);
521 		audio_priv->audio_pdev = NULL;
522 	}
523 }
524 
525 int msm_dp_register_audio_driver(struct device *dev,
526 		struct msm_dp_audio *msm_dp_audio)
527 {
528 	struct msm_dp_audio_private *audio_priv;
529 
530 	audio_priv = container_of(msm_dp_audio,
531 			struct msm_dp_audio_private, msm_dp_audio);
532 
533 	audio_priv->audio_pdev = platform_device_register_data(dev,
534 						HDMI_CODEC_DRV_NAME,
535 						PLATFORM_DEVID_AUTO,
536 						&codec_data,
537 						sizeof(codec_data));
538 	return PTR_ERR_OR_ZERO(audio_priv->audio_pdev);
539 }
540 
541 struct msm_dp_audio *msm_dp_audio_get(struct platform_device *pdev,
542 			struct msm_dp_panel *panel,
543 			struct msm_dp_catalog *catalog)
544 {
545 	int rc = 0;
546 	struct msm_dp_audio_private *audio;
547 	struct msm_dp_audio *msm_dp_audio;
548 
549 	if (!pdev || !panel || !catalog) {
550 		DRM_ERROR("invalid input\n");
551 		rc = -EINVAL;
552 		goto error;
553 	}
554 
555 	audio = devm_kzalloc(&pdev->dev, sizeof(*audio), GFP_KERNEL);
556 	if (!audio) {
557 		rc = -ENOMEM;
558 		goto error;
559 	}
560 
561 	audio->pdev = pdev;
562 	audio->catalog = catalog;
563 
564 	msm_dp_audio = &audio->msm_dp_audio;
565 
566 	msm_dp_catalog_audio_init(catalog);
567 
568 	return msm_dp_audio;
569 error:
570 	return ERR_PTR(rc);
571 }
572 
573 void msm_dp_audio_put(struct msm_dp_audio *msm_dp_audio)
574 {
575 	struct msm_dp_audio_private *audio;
576 
577 	if (!msm_dp_audio)
578 		return;
579 
580 	audio = container_of(msm_dp_audio, struct msm_dp_audio_private, msm_dp_audio);
581 
582 	devm_kfree(&audio->pdev->dev, audio);
583 }
584