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author | Mark Brown <broonie@kernel.org> | 2021-06-14 13:13:53 +0300 |
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committer | Mark Brown <broonie@kernel.org> | 2021-06-14 13:13:53 +0300 |
commit | 116b1e12b72f308b28af5b17081fdb9e1942a8ea (patch) | |
tree | 0cfd3f553c015c1f0ec22075117e2f78c2a5fa00 /Documentation | |
parent | 3ea8a7459861def90bbb184396651d47a4cf4f20 (diff) | |
parent | 2fef64eec23a0840c97977b16dd8919afaffa876 (diff) | |
download | linux-116b1e12b72f308b28af5b17081fdb9e1942a8ea.tar.xz |
Merge tag 'asoc-hdmi-codec-improvements-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux into asoc-5.14
Improvements to the hdmi-codec driver and ALSA infrastructure around it
to support the HDMI Channel Mapping and IEC958 controls
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/sound/kernel-api/writing-an-alsa-driver.rst | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/Documentation/sound/kernel-api/writing-an-alsa-driver.rst b/Documentation/sound/kernel-api/writing-an-alsa-driver.rst index e6365836fa8b..01d59b8aea92 100644 --- a/Documentation/sound/kernel-api/writing-an-alsa-driver.rst +++ b/Documentation/sound/kernel-api/writing-an-alsa-driver.rst @@ -3508,14 +3508,15 @@ field must be set, though). “IEC958 Playback Con Mask” is used to return the bit-mask for the IEC958 status bits of consumer mode. Similarly, “IEC958 Playback Pro Mask” -returns the bitmask for professional mode. They are read-only controls, -and are defined as MIXER controls (iface = -``SNDRV_CTL_ELEM_IFACE_MIXER``). +returns the bitmask for professional mode. They are read-only controls. Meanwhile, “IEC958 Playback Default” control is defined for getting and -setting the current default IEC958 bits. Note that this one is usually -defined as a PCM control (iface = ``SNDRV_CTL_ELEM_IFACE_PCM``), -although in some places it's defined as a MIXER control. +setting the current default IEC958 bits. + +Due to historical reasons, both variants of the Playback Mask and the +Playback Default controls can be implemented on either a +``SNDRV_CTL_ELEM_IFACE_PCM`` or a ``SNDRV_CTL_ELEM_IFACE_MIXER`` iface. +Drivers should expose the mask and default on the same iface though. In addition, you can define the control switches to enable/disable or to set the raw bit mode. The implementation will depend on the chip, but |