On Tue, Mar 14, 2006 at 11:04:37AM -0500, Alfille, Paul H.,M.D. ([EMAIL PROTECTED]) wrote: > Evgeniy, > > I hope I represented w1 correctly. I am excited about being able to use it > with > OWFS. > > My note was more to point out the current state of w1 and OWFS, and to point > out > some of the areas where the two use different approaches. > > For many complex applications, the 1-wire bus utilization is very high. Being > able to control the traffic becomes important. Listing the alarm directory is > a > good example, and controlling when a full bus scan is done. This is in > contrast > to the initial goal of w1: sensor monitoring, where having temperature polling > and alarms should be handled without user intervention. I'm sure we can work > out > a design that works for both. > > Is the netlink socket interface the prefered method? I'm just starting the > design phase and can use netlink or sysfs.
Netlink is definitely the way to go. Sysfs was designed for simple one-shot events, like turn on/turn off. As we saw - simple data reading requires a lot of racy manipulations. Netlink is a UDP-like protocol, which can be used for kernelspace<->userspace or user<->user multicast transfers. Using sequence and acknowledge numbers for request/response design allows to control the whole dataflow. Asynchronous events, like new device found or alarm search results, will be delivered to all "subscribed" applications. > Thanks, > > Paul Alfille > > > -----Original Message----- > From: [EMAIL PROTECTED] on behalf of Evgeniy Polyakov > Sent: Mon 3/13/2006 11:11 AM > To: Paul Alfille > Cc: owfs-developers@lists.sourceforge.net > Subject: [Owfs-developers] Re: w1 changes > > Hello. > > On Wed, Mar 08, 2006 at 12:18:33AM -0500, Paul Alfille ([EMAIL PROTECTED]) > wrote: > > Just a progress report: > > > > After extensive discussions with Evgeniy Polyakov, it looks like OWFS will > > be > > able to use the linux kernel 1-wire drivers as a possible 1-wire adapter > > source. > ... > > Found mail archive with this discussion. I'm not subscribed so please > Cc: me on replies. > > Couple of notes after archive reading: > > 1. w1 supports on-demans searching in the following way: > search is performed on $w1_timeout interval basis, which is provided as > module parameter. By manipulating w1_master_search sysfs file one can > trigger to search or not on next $w1_timeout interval. > 2. I plan to create demo code for netlink socket communication interface for > w1 > this week. This will completely eliminate any kind of races with > multiple workers/reset and so on. > 3. w1 has it's advantages due to it's in-kernel place: > * some processors (Freescale made) have w1 units which can not be > accessed from > userspace without in-kernel driver > * GPIO pins can not be accessed from userspace without in-kernel > driver (actually there is [1] generic GPIO framwork with w1 > driver tested with pc3487x and natsemi sc1100, but work was > frozen > due to lack of hardware) > * w1 supports asynchronous notifications of new devices found, > which are multicasted for any process over netlink > socket interface. > > Probably advertisement should be stopped here. > I'm open for discussion. > > Thank you. > > 1. http://tservice.net.ru/~s0mbre/old/?section=projects&item=soekris > > > Paul Alfille > > -- > Evgeniy Polyakov > > > ------------------------------------------------------- > This SF.Net email is sponsored by xPML, a groundbreaking scripting language > that extends applications into web and mobile media. Attend the live webcast > and join the prime developer group breaking into this new coding territory! > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 > _______________________________________________ > Owfs-developers mailing list > Owfs-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/owfs-developers > -- Evgeniy Polyakov ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
