ab1e9de84a
We have a board where measurements indicate that the current three options - leaving IO_IMPEDANCE_CTRL at the reset value (which is factory calibrated to a value corresponding to approximately 50 ohms) or using one of the two boolean properties to set it to the min/max value - are too coarse. There is no fixed mapping from register values to values in the range 35-70 ohms; it varies from chip to chip, and even that target range is approximate. So add a DT binding for an nvmem cell which can be populated during production with a value suitable for each specific board. Reviewed-by: Rob Herring <robh@kernel.org> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Jakub Kicinski <kuba@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.