Add a helper for the EDID like data structure, which is typically passed
from a HDMI adapter to its associated audio driver.  This informs the
audio driver of the capabilities of the attached HDMI sink.

Signed-off-by: Russell King <redacted>
---
 include/sound/pcm_drm_eld.h |  6 +++
 sound/core/Kconfig          |  3 ++
 sound/core/Makefile         |  1 +
 sound/core/pcm_drm_eld.c    | 91 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 101 insertions(+)
 create mode 100644 include/sound/pcm_drm_eld.h
 create mode 100644 sound/core/pcm_drm_eld.c

diff --git a/include/sound/pcm_drm_eld.h b/include/sound/pcm_drm_eld.h
new file mode 100644
index 000000000000..93357b25d2e2
--- /dev/null
+++ b/include/sound/pcm_drm_eld.h

@@ -0,0 +1,6 @@
+#ifndef __SOUND_PCM_DRM_ELD_H
+#define __SOUND_PCM_DRM_ELD_H
+
+int snd_pcm_hw_constraint_eld(struct snd_pcm_runtime *runtime, void *eld);
+
+#endif

diff --git a/sound/core/Kconfig b/sound/core/Kconfig
index 313f22e9d929..b534c8a6046b 100644
--- a/sound/core/Kconfig
+++ b/sound/core/Kconfig

@@ -6,6 +6,9 @@ config SND_PCM
 	tristate
 	select SND_TIMER
 
+config SND_PCM_ELD
+	bool
+
 config SND_DMAENGINE_PCM
 	tristate
 

diff --git a/sound/core/Makefile b/sound/core/Makefile
index 4daf2f58261c..591b49157b4d 100644
--- a/sound/core/Makefile
+++ b/sound/core/Makefile

@@ -13,6 +13,7 @@ snd-$(CONFIG_SND_JACK)	  += jack.o
 snd-pcm-y := pcm.o pcm_native.o pcm_lib.o pcm_timer.o pcm_misc.o \
 		pcm_memory.o memalloc.o
 snd-pcm-$(CONFIG_SND_DMA_SGBUF) += sgbuf.o
+snd-pcm-$(CONFIG_SND_PCM_ELD) += pcm_drm_eld.o
 
 # for trace-points
 CFLAGS_pcm_lib.o := -I$(src)

diff --git a/sound/core/pcm_drm_eld.c b/sound/core/pcm_drm_eld.c
new file mode 100644
index 000000000000..78d551a1b05f
--- /dev/null
+++ b/sound/core/pcm_drm_eld.c

@@ -0,0 +1,91 @@
+/*
+ *  PCM DRM helpers
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License.
+ */