9a2a566adb
The Allwinner SoCs have on most of their GPIO banks a regulator input. This issue was mainly ignored so far because either the regulator was a static regulator that would be providing power anyway, or the bank was used for a feature unsupported so far (CSI). For the odd cases, enabling it in the bootloader was the preferred option. However, now that we are starting to support those features, and that we can't really rely on the bootloader for this, we need to model those regulators as such in the DT. This is slightly more complicated than what it looks like, since some regulators will be tied to the PMIC, and in order to have access to the PMIC bus, you need to mux its pins, which will need the pinctrl driver, that needs the regulator driver to be registered. And this is how you get a circular dependency. In practice however, the hardware cannot fall into this case since it would result in a completely unusable bus. In order to avoid that circular dependency, we can thus get and enable the regulators at pin_request time. We'll then need to account for the references of all the pins of a particular branch to know when to put the reference, but it works pretty nicely once implemented. Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.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.