On 05/27/2018 01:24 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. > > 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 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@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 Applied to bpf-next, thanks Sean!
