fca18e6298
ASoC dapm controls currently don't support more than 2 channels. This is a problem for SOF-based devices where individual volume control cannot be provided on the 4 DMIC input path. If we want to provide controls for more than 2 channels, this patch suggests a simple solution based on an override of the info callback. For example, in the case with 4 channel DMIC PGAs, a sof_info callback would be used. Mono and stereo cases will keep using the existing dapm info callback. A longer-term solution would be to remove the limits to 2 channels in ASoC/DAPM/topology. This is a topic Intel is currently looking into, e.g. by removing the use of 'reg' and 'rreg' fields and use arrays instead. Such changes will be rather intrusive and touch multiple codec and platform drivers. Removing restrictions is the right thing to do, but this will need to be done in steps with lots of validation. Signed-off-by: Jaska Uimonen <jaska.uimonen@linux.intel.com> Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com> Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com> Link: https://lore.kernel.org/r/20201111173105.1927466-1-kai.vehmanen@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.