From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Date: Sun, 14 Jul 2013 19:57:24 +0000 Subject: Re: [PATCH] misc: add driver for Renesas R-Car Gyro-ADC/speed-pulse interfaces Message-Id: <51E302A4.6080801@cogentembedded.com> List-Id: References: <201307130351.42967.sergei.shtylyov@cogentembedded.com> <20130713005702.GA14788@kroah.com> <51E0AA24.6070203@cogentembedded.com> <201307130958.16533.arnd@arndb.de> <51E1D406.9090702@cogentembedded.com> <51E25D6A.3090106@metafoo.de> In-Reply-To: <51E25D6A.3090106@metafoo.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Lars-Peter Clausen Cc: Arnd Bergmann , Greg KH , linux-kernel@vger.kernel.org, linux-sh@vger.kernel.org Hello. On 07/14/2013 12:12 PM, Lars-Peter Clausen wrote: >>>>> And are you sure you want to control this through sysfs? There's no >>>>> other better user/kernel apis for it? >>>> I found none, besides ioctl(), as the device driven is rather >>>> unique. But I thought that sysfs is "ioctl() today", so I went with it... >>> It does sound like it would fit better into IIO than just a misc driver, >>> even if it's the only hardware of its kind. >> I got somewhat familiarized myself with drivers/iio/ infrastructure and I >> have found a place only the for ADC device in which the customer currently >> has no interest. >> The other trouble is that I'll have to backport this driver to 3.4 which >> doesn't contain the IIO infrastructure at all. :-( > It has, it's just still in staging in 3.4. But the API (except for minor > modifications) and more importantly the ABI are the same. Thank you for the useful information. I wouldn't probably have figured it out to search there. > There is a angular velocity channel type in IIO. maybe that could be used to > report the Speed-Pulse-ADC values. You probably misunderstood from my terse description. Multichannel ADC interface is separate from the speed-pulse interface which has on its single input digital PWM signal of varying frequency. Speed pulse i/f measures pulse count and period. I've found no adequate channel type in IIO infrastructure so far. I'll mail the IIO maintainers with a request for help probably... > - Lars WBR, Sergei