On Tue, 23 Aug 2011 15:07:22 +0100, Jonathan Cameron wrote > On 08/23/11 14:48, malas wrote: > > On Tue, 23 Aug 2011 14:41:57 +0100, Jonathan Cameron wrote > >> On 08/23/11 14:24, malas wrote: > >>> On Tue, 23 Aug 2011 13:58:34 +0100, Jonathan Cameron wrote > >>>> On 08/23/11 13:43, malas wrote: > >>>>> YES : Gregs updated kernel taken from link below: > >>>>> > >>>>> http://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6.git > >>>> Right now that's pretty much mainline. > >>>> > >>>> See comments below and please reply inline as it makes this sort > >>>> of discussion much easier to follow. > >>>>> > >>>>> > >>>>> On Tue, 23 Aug 2011 13:39:12 +0100, Jonathan Cameron wrote > >>>>>> On 08/23/11 13:17, malas wrote: > >>>>>>> > >>>>>>> > >>>>>>> Sorry, I did not explicitly mention that. I did use the new staging kernel > > referred by > >>>>>>> Michael Hennerich and integrated with 2010RC5 uclinux dist . > >>>>>> > >>>>>> Hmm. As in current contents of Greg KH's staging/staging-next? > >>>>>> > >>>>>> I'll assume so... See below. > >>>>>> > >>>>>>> > >>>>>>> On Tue, 23 Aug 2011 12:39:53 +0100, Hennerich, Michael wrote > >>>>>>>> malas wrote on 2011-08-23: > >>>>>>>>> > >>>>>>>>> > >>>>>>>>> Dear Jonathan Cameron, > >>>>>>>>> > >>>>>>>>> The kernel version I am using is : > >>>>>>>> > >>>>>>>> Didn't you say that you use the staging kernel? > >>>>>>>> > >>>>>>>> > >>>>>>> > >>>>> > >>> > > http://blackfin.uclinux.org/gf/project/uclinux-dist/forum/?_forum_action=MessageReply&message_id=102839&action=ForumBrowse > >>>>>>>> > >>>>>>>> Or copied drivers/staging/iio over to your Blackfin kernel tree? > >>>>>>>> > >>>>>>>>> > >>>>>>>>> --------------------------------------------------------------------- > >>>>>>>>> midas@ubuntu:~/Mala/Telemedicine/uclinux_source/uc2010_source/uclinux/2 > >>>>>>>>> 010R1$ svn info Path: . URL: > >>>>>>>>> svn://blackfin.uclinux.org/uclinux-dist/branches/2010R1 Repository Root: > >>>>>>>>> svn://blackfin.uclinux.org/uclinux-dist Repository UUID: > >>>>>>>>> 3e2a5524-39e8-4cb9-84a9-c49da69cba3a Revision: 10161 Node Kind: > >>>>>>>>> directory Schedule: normal Last Changed Author: vapier Last Changed Rev: > >>>>>>>>> 10136 Last Changed Date: 2011-04-02 22:36:15 +0530 (Sat, 02 Apr 2011) > >>>>>>>>> --------------------------------------------------------------------- > >>>>>>>>> > >>>>>>>>> Regards > >>>>>>>>> Mala > >>>>>>>>> > >>>>>>>>> On Tue, 23 Aug 2011 12:21:25 +0100, Jonathan Cameron wrote > >>>>>>>>>> On 08/23/11 09:18, malas wrote: > >>>>>>>>>>> > >>>>>>>>>>> Dear Michael Hennerich, > >>>>>>>>>>> > >>>>>>>>>>> > >>>>>>>>>>> I shall post iio quesris in this mail list as per your suggestions. > >>>>>>>>>>> > >>>>>>>>>>> AD7793 driver is built into kernel. The chip gets configured and am > >>>>>>>>>>> able to read data on continuous mode via spi interface using ad7793 > >>>>>>>>>>> driver at kernel level. > >>>>>>>>>>> > >>>>>>>>>>> While testing userspace test iio-ring to read data from ring buffer, > >>>>>>>>>>> generic_buffer code was executed, it proceeds till opening > >>>>>>>>>>> /sys/bus/iio/devices/device0:buffer0 and Read call fails. > >>>>>>>>>> Question 1: What's the kernel and where did you get it from? > >>>>>>>>>> (Interfaces are moving fast so it's plausible you've fallen in a hole > >>>>>>>>>> where userspace wasn't matching kernelspace). > >>>>>>>>>>> > >>>>>>>>>>> In fs I can list the iio device ad7793 with following properties > >>>>>>>>>>> get/set. > >>>>>>>>>>> > >>>>>>>>>>> root:/> ls /sys/bus/iio/devices/device0\:buffer0/ > >>>>>>>>>>> bytes_per_datum enable power subsystem > >>>>>>>>>>> dev length scan_elements uevent > >>>>>>>>>>> root:/> > >>>>>>>>>>> > >>>>>>>>>>> I find access0 and event0 missing in this list. Is that the reason > >>>>>>>>> for read() fails. > >>>>>>>>>> Yes. Question is why and without kernel version I don't know where to > >>>>>>>>>> look I'm afraid. > >>>>>> Ah, this does look like a missmatch in interfaces between userspace and kernel. > >>>>>> > >>>>>> At this point in time we have scrapped the event0 chrdev (done via polling on > >>>>>> the access one) and the access one has be flattened into device0\:buffer0/ > >>>>>> (read dev). > >>>>>> > >>>>>> Looks like the generic_buffer.c example does line up though. Where did the > >>>>>> 'test iio-ring' come from? Is that one yours Michael? > >>> > >>> > >>> iio-ring.c under uclinux2010/user/blkfin-test/iio-ring-test. The file is in the > >>> attached. I did not use that since i didn't find access0 or event0 files under > >>> /sys/bus/iio/devices/device0:buffer0. > >>> > >>> I have tested with the generic_buffer.c example (under iio/documentaion folder) to get > >>> Ad7793 received samples to user space from ring buffer. > >>> The app opens: /dev/device0:buffer0 for poll and reading samples. > >>> Is the device name for the open() correct. > >> Yes - that should be right. > > ************************* > > Open fails for "/dev/device0:buffer0" device name > > I tried changing to "/sys/bus/iio/devices/device0:buffer0"- open() succeeded then but > > then read fails. > Read must be the one under dev. The other is a directory with description of > the buffer. > > What is the error on the open of /dev/device0:buffer0? ERROR => Going to open access file /dev/device0:buffer0 Failed to open /dev/device0:buffer0 open returned fp as -1 -- Open WebMail Project (http://openwebmail.org) -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
