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Daniel Borkmann
ee7dbd9747
Sean Young says: ==================== The kernel IR decoders (drivers/media/rc/ir-*-decoder.c) support the most widely used IR protocols, but there are many protocols which are not supported[1]. For example, the lirc-remotes[2] repo has over 2700 remotes, many of which are not supported by rc-core. There is a "long tail" of unsupported IR protocols, for which lircd is need to decode the IR . IR encoding is done in such a way that some simple circuit can decode it; therefore, bpf is ideal. In order to support all these protocols, here we have bpf based IR decoding. The idea is that user-space can define a decoder in bpf, attach it to the rc device through the lirc chardev. Separate work is underway to extend ir-keytable to have an extensive library of bpf-based decoders, and a much expanded library of rc keymaps. Another future application would be to compile IRP[3] to a IR BPF program, and so support virtually every remote without having to write a decoder for each. It might also be possible to support non-button devices such as analog directional pads or air conditioning remote controls and decode the target temperature in bpf, and pass that to an input device. [1] http://www.hifi-remote.com/wiki/index.php?title=DecodeIR [2] https://sourceforge.net/p/lirc-remotes/code/ci/master/tree/remotes/ [3] http://www.hifi-remote.com/wiki/index.php?title=IRP_Notation Changes since v4: - Renamed rc_dev_bpf_{attach,detach,query} to lirc_bpf_{attach,detach,query} - Fixed error path in lirc_bpf_query - Rebased on bpf-next Changes since v3: - Implemented review comments from Quentin Monnet and Y Song (thanks!) - More helpful and better formatted bpf helper documentation - Changed back to bpf_prog_array rather than open-coded implementation - scancodes can be 64 bit - bpf gets passed values in microseconds, not nanoseconds. microseconds is more than than enough (IR receivers support carriers upto 70kHz, at which point a single period is already 14 microseconds). Also, this makes it much more consistent with lirc mode2. - Since it looks much more like lirc mode2, rename the program type to BPF_PROG_TYPE_LIRC_MODE2. - Rebased on bpf-next Changes since v2: - Fixed locking issues - Improved self-test to cover more cases - Rebased on bpf-next again Changes since v1: - Code review comments from Y Song <ys114321@gmail.com> and Randy Dunlap <rdunlap@infradead.org> - Re-wrote sample bpf to be selftest - Renamed RAWIR_DECODER -> RAWIR_EVENT (Kconfig, context, bpf prog type) - Rebase on bpf-next - Introduced bpf_rawir_event context structure with simpler access checking ==================== Signed-off-by: Daniel Borkmann <daniel@iogearbox.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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.