malas wrote on 2011-08-23: > 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=ForumBr > owse >>>>>>>>>> >>>>>>>>>> Or copied drivers/staging/iio over to your Blackfin kernel tree? >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> ----------------------------------------------------------- >>>>>>>>>>> ---------- >>>>>>>>>>> >>>>>>>>>>> midas@ubuntu:~/Mala/Telemedicine/uclinux_source/uc2010_source/u >>>>>>>>>>> clinux/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 > I think I asked you before to check if /dev/device0:buffer0 exists. And I guess is does not - so you have to create it. Greetings, Michael -- Analog Devices GmbH Wilhelm-Wagenfeld-Str. 6 80807 Muenchen Sitz der Gesellschaft: Muenchen; Registergericht: Muenchen HRB 40368; Geschaeftsfuehrer:Dr.Carsten Suckrow, Thomas Wessel, William A. Martin, Margaret Seif -- 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
