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. Thanks, Sean Young [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 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@xxxxxxxxx> and Randy Dunlap <rdunlap@xxxxxxxxxxxxx> - 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 Sean Young (2): media: rc: introduce BPF_PROG_RAWIR_EVENT bpf: add selftest for rawir_event type program drivers/media/rc/Kconfig | 13 + drivers/media/rc/Makefile | 1 + drivers/media/rc/bpf-rawir-event.c | 363 ++++++++++++++++++ drivers/media/rc/lirc_dev.c | 24 ++ drivers/media/rc/rc-core-priv.h | 24 ++ drivers/media/rc/rc-ir-raw.c | 14 +- include/linux/bpf_rcdev.h | 30 ++ include/linux/bpf_types.h | 3 + include/uapi/linux/bpf.h | 55 ++- kernel/bpf/syscall.c | 7 + tools/bpf/bpftool/prog.c | 1 + tools/include/uapi/linux/bpf.h | 57 ++- tools/lib/bpf/libbpf.c | 1 + tools/testing/selftests/bpf/Makefile | 8 +- tools/testing/selftests/bpf/bpf_helpers.h | 6 + tools/testing/selftests/bpf/test_rawir.sh | 37 ++ .../selftests/bpf/test_rawir_event_kern.c | 26 ++ .../selftests/bpf/test_rawir_event_user.c | 130 +++++++ 18 files changed, 792 insertions(+), 8 deletions(-) create mode 100644 drivers/media/rc/bpf-rawir-event.c create mode 100644 include/linux/bpf_rcdev.h create mode 100755 tools/testing/selftests/bpf/test_rawir.sh create mode 100644 tools/testing/selftests/bpf/test_rawir_event_kern.c create mode 100644 tools/testing/selftests/bpf/test_rawir_event_user.c -- 2.17.0
