feebfe95a6
In current configuration, nau8822 codec on development carrier board provides distorted audio output. This happens due to reference clock is fixed to 25MHz and no PLL is enabled. Following is the calculation of deviation error for different frequencies: 44100Hz: fs = 256 (fixed) prescaler = 2 target frequency = 44100 * 256 * 2 = 22579200 deviation = 22579200 vs 25000000 = 9.6832% 48000Hz: fs = 256 (fixed) prescaler = 2 target frequency = 48000 * 256 * 2 = 24576000 deviation = 24576000 vs 25000000 = 1.696% Enabling nau822 PLL via providing mclk-fs property to simple-audio-card configures clocks properly, but also adjusts audio reference clock (mclk), which in case of TI AM62 should be avoided, as it only supports 25MHz output [1][2]. This change enables PLL on nau8822 by providing mclk-fs, and moves away audio reference clock from DAI configuration, which prevents simple-audio-card to adjust it before every playback [3]. [1]: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1175479/processor-sdk-am62x-output-audio_ext_refclk0-as-mclk-for-codec-and-mcbsp/4444986#4444986 [2]: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1188051/am625-audio_ext_refclk1-clock-output---dts-support/4476322#4476322 [3]: sound/soc/generic/simple-card-utils.c#L441 Signed-off-by: Andrejs Cainikovs <andrejs.cainikovs@toradex.com> Reviewed-by: Francesco Dolcini <francesco.dolcini@toradex.com> Link: https://lore.kernel.org/r/20240418105730.120913-1-andrejs.cainikovs@gmail.com Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
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 reStructuredText 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.