> Am 18.02.2015 um 15:34 schrieb Martin Rapavy: > > To add some technical details to my query: the bus master chip in > > question si very similiar to DS1WM (which is something like > > DS2482-800 but with memory-mapped registers, instead of I2C access). > > After browsing the sources for some time I concluded that without > > guidance from developers it's going to be very hard to identify all > > the places where to hook-in support for new bus master. > > > Option A > -------- > OWFS supports the DS1WM through the w1 kernel driver (--w1 option). On a > Linux box, that it be sufficient if you fork the kernel driver for DS1WM > or add support for you chip in there. The disadvantage is the w1 kernel > driver polls the bus itself for new devices and so, isn't a 100% drop-in > for a native owfs driver. 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)?
> 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. > 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. Thank you for your thoughts and ideas. Best regards, Martin > Choose your poison. I favour B. > > > 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
