Re: ad7793 iio-ring test read issue - Reg

[Jonathan Cameron <jic23@cam.ac.uk>]

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? 
>>>>
>>>>>
>>>>> Please help.
>>>>>
>>>>> Thanks
>>>>> Mala
>>>>> --
>>>>> Open WebMail Project (http://openwebmail.org)
>