forked from Minki/linux
mainlining shenanigans
e7a96b0b7d
The AST2400 and AST2500 SoCs only exposed one pin group per function. Lone pin groups drove some implementation simplifications in the ASPEED pinmux infrastructure that is now invalid for the AST2600, which supports multiple groups per function for some functions on the chip (SMBus Alert pins and UARTs among others). This patch reworks the macro jungle to enable support for multiple pin groups. In the process we inflict some collateral damage on the existing AST2400 and AST2500 drivers, but the rework is mostly a relatively straight-forward, automated transform of adding the pin name as an argument to some macro calls and implementing wrappers to paper over groups in the cases where there aren't multiple. As previously documented, the macro infrastructure exposes mux configuration as symbols in the source file which are used to detect accidental duplication. Previously these symbols were named in terms of the signal for a given expression. As the AST2600 supports multiple pin groups for a function, the signal name on its own is no-longer unique, and we must switch to the (signal, group) tuple. However, this means that we can no-longer derive the signal expression symbol name from the signal name alone, which among other cases, impacts the operation of the PIN_DECL_x() macros. To fix that and avoid requiring we awkwardly provide the associated group name for every signal for every PIN_DECL_x() invocation, instead opportunistically alias the name of the signal expression symbol from the unique (signal, group) tuple to the also unique (pin, signal) tuple, then reference the alias symbol in the tables generated by PIN_DECL_x(). This way we do not require extra group parameters for PIN_DECL_x() as the pin name was already provided as an argument, and instead simply require that the pin name be provided to the expression declaration macros in order to generate the alias symbol. The patch implements the alias strategy and fixes up all the expression definition macro calls in the AST2400 and AST2500 drivers to account for pin groups. Given the implementation strategy has the property that compilation either fails or loudly warns for bad pin descriptions, this patch is theoretically tested by successfully compiling both affected drivers. For a more practical test I've inspected the diff of the content of the pinctrl debugfs entries before and after the patch under qemu; all pins, functions and groups match. Signed-off-by: Andrew Jeffery <andrew@aj.id.au> Link: https://lore.kernel.org/r/20190729055604.13239-5-andrew@aj.id.au Signed-off-by: Linus Walleij <linus.walleij@linaro.org> |
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| init | ||
| ipc | ||
| kernel | ||
| lib | ||
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| .clang-format | ||
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| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
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| Kbuild | ||
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| README | ||
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.