53778b8292
AK4375 is a 32-bit stereo DAC with headphones amplifier. There's no documentation for it on akm.com, and only a brief datasheet can be found floating on the internets [1]. Thanks to Oriane BAYERD <obayerd@eurocomposant.fr> for finally answering my inquiries through akm.com, if only to tell me that this chip is EOL following AKM factory burning in october 2020 and thus no detailed documentation is available anymore... AK4331 is advertised [2] as pin and register compatible with AK4375 so some scraps of its datasheet were used and this driver might be used as a base for it, but this is totally untested. So this driver is mainly based on downstream code [3] and [4] by Hu Jin from AKM (no known email). Tested on msm8916-alcatel-idol347 and msm8939-alcatel-idol3, which both use PLL driven clock with bypass of SRC (sample rate converter), so only this setup is supported for now. [1] https://datasheetspdf.com/pdf-file/1400317/AKM/AK4375A/1 [2] https://www.akm.com/content/dam/documents/products/audio/audio-dac/ak4331ecb/ak4331ecb-en-datasheet.pdf [3] https://github.com/msm8916-mainline/android_kernel_qcom_msm8916/blob/alcatel-idol347/sound/soc/codecs/idol347/ak4375.c [4] https://github.com/msm8916-mainline/android_kernel_qcom_msm8916/blob/alcatel-idol347/sound/soc/codecs/ak4375.c Signed-off-by: Vincent Knecht <vincent.knecht@mailoo.org> Link: https://lore.kernel.org/r/20211220193725.2650356-2-vincent.knecht@mailoo.org 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.