Re: Query related to MSR(Magnetic Stripe Reader) Device Driver

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Jan 28, 2013 at 03:25:08PM +0530, Priyaranjan Das wrote:
> Hi Greg,
> 
> On Tue, Jan 22, 2013 at 10:06 PM, Greg KH <gregkh@linuxfoundation.org> wrote:
> > On Tue, Jan 22, 2013 at 03:02:32PM +0530, Priyaranjan Das wrote:
> >> Hi All,
> >>
> >> I am working on MSR(Magnetic Stripe Reader) for a product . I wish to
> >> know whether any MSR( Magnetic Stripe/card Reader) driver is available
> >> in the current source or not. I need this for reference. Could anyone
> >> please help me?
> >
> > Most of these types of devices that I have worked with always show up as
> > a keyboard device (ps/2 pass-through or a USB hid device.)  What type of
> > interface does your device present to the operating system?
> >
> 
> The MSR will be a part of a SoC. It is  a memory mapped device hence
> there is no interface like USB.

Ok, that's different.  But how will your driver want to communicate the
reader data to userspace?  That will probably determine where you want
to put it.

I would recommend making it an input device and sending keystrokes that
you read from the card, so you can properly integrate into userspace
applications that are used to using a card reader.

> MSR IP contains an ADC which the driver will read and interpret the
> data. I am planning to write a Driver for the same. Will this driver
> fall under drivers/mfd/* ?

As per the above, I would think drivers/input/ wouldn't you?

Hope this helps,

greg k-h