From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:41342 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753130Ab3GPIbQ (ORCPT ); Tue, 16 Jul 2013 04:31:16 -0400 Message-ID: <51E504D2.5030000@kernel.org> Date: Tue, 16 Jul 2013 09:31:14 +0100 From: Jonathan Cameron MIME-Version: 1.0 To: Sergei Shtylyov CC: Jonathan Cameron , linux-iio@vger.kernel.org, linux-sh@vger.kernel.org Subject: Re: Help with fitting unusual devices into IIO framework References: <51E46F7A.9020400@cogentembedded.com> In-Reply-To: <51E46F7A.9020400@cogentembedded.com> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 07/15/2013 10:54 PM, Sergei Shtylyov wrote: > Hello. > One quick point first, if you could persuade your email client to wrap at 80 characters that would be great. > Recently I have posted a driver for drivers/misc/ driving a pair of devices: Renesas R-Car > Gyro-ADC and speed-pulse interfaces [1]. Arnd Bergmann, one of the maintainers told me > that such driver would fit better into the IIO infrastructure. I have studied this > infrastructure for some time and only found in it a place for the Gyro-ADC > interface. > Let me describe the devices to be driven in some detail. Gyro-ADC i/f is an > interface to multichannel serial ADC (of 3 certain models) which can also calculate and > average of each 8 samples and sum up 10 of these average values. That is indeed fairly standard although some of the ABI for summed values is still under discussion. http://thread.gmane.org/gmane.linux.kernel.iio/7978/focus=79864 for example. > Speed-pulse interface > can count PWM-type input signal pulses and period between them. Though being > two separate devices, these two have to be driven together because of the shared > start/stop register (located in Gyro-ADC i/f still) and the clock with 1.25 ms period > supplied from the Gyro-ADC i/f to the speed-pulse i/f; at the same time speed-pulse i/f > generates interrupt with 100 ms period to be used by both interfaces. At this time, only > speed-pulse interface support is required, Gyro-ADC can be largely ignored (though it > has to be initialized). Perhaps we could add a new I/O channel type for speed-pulse i/f? > What's your thoughts? I certainly have no problem with adding this device type. Would you like to propose a suitable ABI addition to /Documentation/ABI/test/sysfs-bus-iio to cover this type of device. I do vaguely wonder if we would be better treating these entirely generically as pulse counters rather than specifically as being for speed measurement? (Note I have only the sketchiest idea of what this device actually does ;) > > [1] marc.info/?l=linux-kernel&m=137367311823027 > > WBR, Sergei > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html