On 05/18/2018 04:07 PM, Sean Young wrote: > 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.
Mauro, are you fine with this series going via bpf-next? How ugly would this get with regards to merge conflicts wrt drivers/media/rc/? Thanks, Daniel > 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 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 <ys114...@gmail.com> and > Randy Dunlap <rdun...@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 > > Sean Young (3): > bpf: bpf_prog_array_copy() should return -ENOENT if exclude_prog not > found > media: rc: introduce BPF_PROG_LIRC_MODE2 > bpf: add selftest for lirc_mode2 type program > > drivers/media/rc/Kconfig | 13 + > drivers/media/rc/Makefile | 1 + > drivers/media/rc/bpf-lirc.c | 308 ++++++++++++++++++ > drivers/media/rc/lirc_dev.c | 30 ++ > drivers/media/rc/rc-core-priv.h | 22 ++ > drivers/media/rc/rc-ir-raw.c | 12 +- > include/linux/bpf_rcdev.h | 30 ++ > include/linux/bpf_types.h | 3 + > include/uapi/linux/bpf.h | 53 ++- > kernel/bpf/core.c | 11 +- > kernel/bpf/syscall.c | 7 + > kernel/trace/bpf_trace.c | 2 + > tools/bpf/bpftool/prog.c | 1 + > tools/include/uapi/linux/bpf.h | 53 ++- > tools/include/uapi/linux/lirc.h | 217 ++++++++++++ > tools/lib/bpf/libbpf.c | 1 + > tools/testing/selftests/bpf/Makefile | 8 +- > tools/testing/selftests/bpf/bpf_helpers.h | 6 + > .../testing/selftests/bpf/test_lirc_mode2.sh | 28 ++ > .../selftests/bpf/test_lirc_mode2_kern.c | 23 ++ > .../selftests/bpf/test_lirc_mode2_user.c | 154 +++++++++ > 21 files changed, 974 insertions(+), 9 deletions(-) > create mode 100644 drivers/media/rc/bpf-lirc.c > create mode 100644 include/linux/bpf_rcdev.h > create mode 100644 tools/include/uapi/linux/lirc.h > create mode 100755 tools/testing/selftests/bpf/test_lirc_mode2.sh > create mode 100644 tools/testing/selftests/bpf/test_lirc_mode2_kern.c > create mode 100644 tools/testing/selftests/bpf/test_lirc_mode2_user.c >
