From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:36567 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751486Ab3CBQ1Q (ORCPT ); Sat, 2 Mar 2013 11:27:16 -0500 Message-ID: <51322863.4070901@kernel.org> Date: Sat, 02 Mar 2013 16:27:15 +0000 From: Jonathan Cameron MIME-Version: 1.0 To: Chris Micali CC: Lars-Peter Clausen , "linux-iio@vger.kernel.org" Subject: Re: IIO Drivers References: <26387F1A648A4D3D9BB4142C4F0AAE98@gmail.com> <512E2F31.8000604@metafoo.de> <512E3592.4020702@metafoo.de> <4AEA8015FE824807B3CF62B7B35FC5D3@gmail.com> <512E43A9.4090301@metafoo.de> <5277B88AB1FF4E6A83920766C0BE13F7@gmail.com> <512E5054.8030905@kernel.org> <512E55AA.6050203@metafoo.de> <5CCB32D4B146494F902390C27F8216A8@gmail.com> In-Reply-To: <5CCB32D4B146494F902390C27F8216A8@gmail.com> Content-Type: text/plain; charset=UTF-8 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 02/27/2013 07:32 PM, Chris Micali wrote: > Guys, > > Thanks a lot for the help! I finally tracked down issues, it was a combination of a few things: > > 1. The .channel had to be 0, not 1 in the driver (scan_index didn't matter) > 2. 1 or more scan_elements have to be enabled as you mentioned > 2. When echoing into the sysfs files it has to have a space after the number (cat 1 > in_voltage0_en and not cat 1>in_vo…) (duh!) > 3. The generic_buffer.c program had a few bugs in it causing crashes. I updated the iio_utils.h to a newer version I found here: https://github.com/analogdevicesinc/iio-oscilloscope and then made a few modifications (the newer iio_utils did not parse a few things right in the channel details like bigendian/littleendian) > > So generic_buffer is now correctly sampling (although it crashes after a couple, it's probably another iio_utils issue) > If you do track down why this is happening, please do report back so we can get it fixed. I wasn't previously aware of any particular issues in the example code so any feedback is helpful! Looking foward to seeing the driver code when you are happy with it. Jonathan > Thanks!! > > -chris > > > On Wednesday, February 27, 2013 at 1:51 PM, Lars-Peter Clausen wrote: > >> On 02/27/2013 07:28 PM, Jonathan Cameron wrote: >>> On 02/27/2013 05:36 PM, Chris Micali wrote: >>>> lars, >>>> >>>> I was under the impression that flag gets added automatically by iio_triggered_buffer_setup (industrialiio-triggers.c:77) - I actually am now able to enable the scan_element after changing my channel .channel and .scan_index to 0 (trying to match exactly the other drivers.) >> >> Yea, you are right I missed the iio_triggered_buffer_setup part. >> >>> Strange, scan_index should have defaulted to zero and the .channel value shouldn't have mattered >>> for buffered reads (just effects naming). Might have caused issues with userspace expecting a channel 0 >>> though... >> >> >> >> I guess the scan_index had nothing to do with this, but I suggested to set >> scan_elements/in_voltage0_en to 1, so this clearly wouldn't have worked with >> .channel being 1. >> >>> >>>> When i run general_buffer (from the docs dir) with that scan element enabled it can no longer read the trigger (Could not open /trigger/current_trigger Failed to write current_trigger file) - this succeeds if that scan_element is not enabled. >> >> You can't change the trigger if the buffer is currently enabled. Make sure that >> he buffer is disabled (check the buffer/enable attribute). >> >> - Lars >> u > > >