On Sun, 20 Jun 2004 16:51:31 +0400 Evgeniy Polyakov <johnpol at 2ka.mipt.ru> wrote: Ping. iButton support will coming soon. > Hello. > I have some notes about such devices and design of the Linux kernel w1 > implementation. > > 1. After rereading specs for various *<->w1 master > devices I found that all they do support bit interface since it is > required by w1 search algorithm. Maybe some devices exist that drive > some register when they found new slave device on the bus and provide > it's address in other register, and also such devices require flags > that indicates that search must be proceeded or stopped. > I don't now about such devices, but if they exist one can easily > update w1 master operations structure to support search callback for > it, and main master's ->process() routing to call it instead of > default bit-banging w1_search() call. I will do it if you provide > datasheet. > > 2. By design I leave main master's ->process() call as easy as > possible and move all data processing out to slave device > drivers(family drivers). Master just searches for devices on the bus, > requests it's drivers and provide them all needed functionality. > Now I extended a bit w1 master operations to support > read_/write_byte() and reset_bus() calls, so if provided they will be > called before bit operations. > > So in case of DS2490 you just need to write driver implementing > read_bit and write_bit operations using some USB commands, then > register it as master. Any slave devices that will be found in bus > connected to DS2490 will use automatically any operations that you > will provide, but they actually needs only bit operations. Others are > just extensions. > > Thank you for review and comments. Evgeniy Polyakov ( s0mbre ) Only failure makes us experts. -- Theo de Raadt -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: MAINTAINERS.diff Url: http://lists.lm-sensors.org/pipermail/lm-sensors/attachments/20040703/ed72d948/attachment.pl -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: drivers_Kconfig.diff Url: http://lists.lm-sensors.org/pipermail/lm-sensors/attachments/20040703/ed72d948/attachment-0001.pl -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: drivers_Makefile.diff Url: http://lists.lm-sensors.org/pipermail/lm-sensors/attachments/20040703/ed72d948/attachment-0002.pl -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: w1.diff Url: http://lists.lm-sensors.org/pipermail/lm-sensors/attachments/20040703/ed72d948/attachment-0003.pl
