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authorTakashi Iwai <tiwai@suse.de>2021-07-01 08:36:12 +0200
committerTakashi Iwai <tiwai@suse.de>2021-07-01 08:36:12 +0200
commit50de417b7a5bfe8ab5c571427703f67c934736dc (patch)
treec791889f8e1c325e286eea593743cc4a24732e07 /Documentation/sound
parentALSA: scarlett2: Fix scarlett2_*_ctl_put() return values again (diff)
parentMerge remote-tracking branch 'asoc/for-5.14' into asoc-next (diff)
downloadlinux-50de417b7a5bfe8ab5c571427703f67c934736dc.tar.xz
linux-50de417b7a5bfe8ab5c571427703f67c934736dc.zip
Merge tag 'asoc-v5.14' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Updates for v5.14 This release sees a nice new feature in the core from Morimoto-san, support for automatic negotiation of DAI formats between the components on the link. Otherwise the big highlight was the merging of the Tegra machine drivers into a single driver avoiding a bunch of duplication. - Support for automatic negotiation of DAI formats. - Accessory detection support for several Qualcomm parts. - Support for IEC958 control with hdmi-codec. - Merging of Tegra machine drivers into a single driver. - Support for AmLogic SM1 TOACODEC, Intel AlderLake-M, several NXP i.MX8 variants, NXP TFA1 and TDF9897, Rockchip RK817, Qualcomm Quinary MI2S, Texas Instruments TAS2505
Diffstat (limited to 'Documentation/sound')
-rw-r--r--Documentation/sound/kernel-api/writing-an-alsa-driver.rst13
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