> Am 18.02.2015 um 21:19 schrieb Martin Rapavy: > > I was exactly in favor of avoiding w1 because of bus polling. It is > > important for me not to use the bus frequently (the wire is also > > shared for reading out data from sensors). Do you think that the w1 > > polling might be turned off using w1_master_search (w1 sysfs > > interface)? > > > That's exactly the purpose of this node. OWFS sends an explicit search > command through the netlink socket to the w1 driver at > > module/owlib/src/c/ow_w1.c, line 112ff > > so turning off w1_master_search only affects other services which rely > on it. BUT: depending on your hardware, hot-plugging a battery may > already rely on this! It's a bit of a pity this is a global flag and > cannot be turned off by bus. Check your hardware whether it has other > services on another onewire.
> Second pitfall: if your hardware has several buses, the w1 driver will > all join them into one. I guess this is really a deal-breaker. There really might be multiple buses (onewire channels) connected to that piece of hardware. > Nevertheless, patching the DS1WM w1 driver may be sufficient and easy > enough. > > > >> Option B -------- Write a fake I²C host adaptor kernel driver which > >> creates a new "I²C bus", with your onewire host adaptor the only > >> device "connected" to that "bus. This may be the easiest option if > >> your device behaves very much like the original DS2482. OWFS drops > >> in neatly, no strings attached. > > > > I like this approach but I guess I should have been more clear on > similarity with DS2482 -- it is conceptually similar (hardware based > multichannel bus master chip) but the interface is different. The > interface of that custom chip closely matches DS1WM. > > Then this is *not* the way to go. > > > > >> Option C -------- Memory-mapped IO from userspace, which is *UGH!*. > >> See module/owlib/src/c/ow/ow_ds2482.c for all the things to write > >> and change. The disadvantage is owfs has to run as root to do > >> MMIO. > > I don't mind running under root. I suppose this is the only feasible > > option if I don't want to use Linux w1. I will have a look into that > > source. > > > Well, if you don't show it to anyone... (^__^); I'm aware of non-reusability of that solution but on the other hand also quite specific piece of hardware and from your selection of choices I don't see any other way. Am I right? Best regards, Martin > Kind regards > > Jan ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=190641631&iu=/4140/ostg.clktrk _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
