1734b4135a
This patch adds support for these devices: - YH-5151E - the PDU - YM-2151E - the PSU The device datasheet says that the devices support PMBus 1.2, but in my testing, a lot of the commands aren't supported and if they are, they sometimes behave strangely or inconsistently. For example, writes to the PAGE command requires using PEC, otherwise the write won't work and the page won't switch, even though, the standard says that PEC is optional. On the other hand, writes to SMBALERT don't require PEC. Because of this, the driver is mostly reverse engineered with the help of a tool called pmbus_peek written by David Brownell (and later adopted by my colleague Jan Kundrát). The device also has some sort of a timing issue when switching pages, which is explained further in the code. Because of this, the driver support is limited. It exposes only the values that have been tested to work correctly. Signed-off-by: Václav Kubernát <kubernat@cesnet.cz> Link: https://lore.kernel.org/r/20210414080019.3530794-1-kubernat@cesnet.cz [groeck: Fixed up "missing braces around initializer" from 0-day] Signed-off-by: Guenter Roeck <linux@roeck-us.net>
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.