Linux mainline fork with MSM8998 patches | https://mainline.space | Currently supported devices:
OnePlus 5/5T, Xiaomi Mi 6, F(x)tec Pro¹ (2019 QX1000 model) & Sony Xperia XZ Premium (UNTESTED!)
03528b4dc3
This driver is a reimplementation of matrix_keyboard, on which it is heavily based: the former was made back in 2009 and then lightly updated in 2012 to add some support for device-tree / OF. It turns out that this is not enough, nor OF is fully supported, as the global (or "clustered") interrupt is never probed, nor it made usage of the GPIOD API which, nowadays, really simplifies the job - but not only: it also provides means to set GPIO arrays for controllers that are supporting this. The latter is very important when dealing with slow GPIOs such as I2C and/or SPI expanders (and, again, not only); by using the new APIs everything fits the new systems, from simplifications of the probe/remove functions to opening possibility of using expanders to drive key matrices with or without protection diodes. But then, why wasn't the old matrix_keyboard driver modified instead of creating a new one? The problem there is that the old driver is made to support the old platform_device style and it's currently still being used by some PXA boards that are not (yet?) ported to device-tree, so it would be impossible to modernize it for good, which means that to support GPIOD (which is - really - required for the aforementioned reasons) and to fully support DT it would be necessary to wrap the old GPIO API around the new GPIOD one, creating overhead and also probably unnecessary memory usage, other than a very big driver which, at least on embedded devices (having limited resources), would be simply bad. Leaving the fact that I haven't got any old board so it's impossible for me to analyze and optimize for them. Since 98% of the users of the old driver are infact platforms that have been ported to (or are born with) DT, the introduction of a new driver that's purely made for them seemed to be the best choice, also because the expectations are (I think) that all of the old ARM-based boards will be ported to DT anyway, which will actually deprecate the good old matrix_keyboard driver. Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org> |
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| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| 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.