a03a915b83
The TDA998x derives the CTS value using the supplied I2S bit clock (ACLK, in TDA998x parlence) rather than 128·fs. TDA998x uses two constants named m and k in the CTS generator such that we have this relationship between the I2S source ACLK and the sink fs: 128·fs_sink = ACLK·m / k Where ACLK = aclk_ratio·fs_source. When audio support was originally added, we supported a fixed ratio of 64·fs, intending to support the Kirkwood I2S on Dove. However, when hdmi-codec support was added, this was changed to scale the ratio with the sample width, which would've broken its use with Kirkwood I2S. We are now starting to see other users whose I2S blocks send at 64·fs for 16-bit samples, so we need to reinstate the support for the fixed ratio I2S bit clock. This commit takes a step towards supporting these configurations by selecting the CTS_N register m and k values based on the bit clock ratio. However, as the driver is not given the bit clock ratio from ALSA, continue deriving this from the sample width. This will be addressed in a later commit. Tested-by: Sven Van Asbroeck <TheSven73@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
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.