linux-kernel - Re: [PATCH] misc: add driver for Renesas R-Car Gyro-ADC/speed-pulse interfaces

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <51E302A4.6080801@cogentembedded.com>
Date:	Sun, 14 Jul 2013 23:57:24 +0400
From:	Sergei Shtylyov <sergei.shtylyov@...entembedded.com>
To:	Lars-Peter Clausen <lars@...afoo.de>
CC:	Arnd Bergmann <arnd@...db.de>,
	Greg KH <gregkh@...uxfoundation.org>,
	linux-kernel@...r.kernel.org, linux-sh@...r.kernel.org
Subject: Re: [PATCH] misc: add driver for Renesas R-Car Gyro-ADC/speed-pulse
 interfaces

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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/