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Linus Walleij
f69e00bd21
It turns out that one specific hardware has two direction registers: one to set a GPIO line as input and another one to set a GPIO line as output. So in theory a line can be configured as input and output at the same time. Make the MMIO GPIO helper deal with this: store both registers in the state container, use both in the generic code if present. Synchronize the input register to the output register when we register a GPIO chip, with the output settings taking precedence. Keep the helper variable to detect inverted direction semantics (only direction in register) but augment the code to be more straight-forward for the generic case when setting the registers. Fix some flunky with unreadable direction registers at the same time as we're touching this code. Cc: David Woods <dwoods@mellanox.com> Cc: Shravan Kumar Ramani <sramani@mellanox.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
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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.