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author | Jani Nikula <jani.nikula@intel.com> | 2014-10-27 16:27:00 +0200 |
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committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2014-11-07 18:42:19 +0100 |
commit | 28855d2ac349b3fbb285c38493429dd1aa503523 (patch) | |
tree | 2748c3717f14023f36b9fcb3a40f21cdbbb9895f /drivers/gpu/drm/i915/intel_audio.c | |
parent | 82910ac6d575d4ce4bd4dcefb61923623b263e00 (diff) | |
download | op-kernel-dev-28855d2ac349b3fbb285c38493429dd1aa503523.zip op-kernel-dev-28855d2ac349b3fbb285c38493429dd1aa503523.tar.gz |
drm/i915/audio: add DOC comment describing HDA over HDMI/DP
v2: include the section in the drm docbook.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm/i915/intel_audio.c')
-rw-r--r-- | drivers/gpu/drm/i915/intel_audio.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c index 9181b85d..44c49df 100644 --- a/drivers/gpu/drm/i915/intel_audio.c +++ b/drivers/gpu/drm/i915/intel_audio.c @@ -28,6 +28,27 @@ #include "intel_drv.h" #include "i915_drv.h" +/** + * DOC: High Definition Audio over HDMI and Display Port + * + * The graphics and audio drivers together support High Definition Audio over + * HDMI and Display Port. The audio programming sequences are divided into audio + * codec and controller enable and disable sequences. The graphics driver + * handles the audio codec sequences, while the audio driver handles the audio + * controller sequences. + * + * The disable sequences must be performed before disabling the transcoder or + * port. The enable sequences may only be performed after enabling the + * transcoder and port, and after completed link training. + * + * The codec and controller sequences could be done either parallel or serial, + * but generally the ELDV/PD change in the codec sequence indicates to the audio + * driver that the controller sequence should start. Indeed, most of the + * co-operation between the graphics and audio drivers is handled via audio + * related registers. (The notable exception is the power management, not + * covered here.) + */ + static const struct { int clock; u32 config; |