From mboxrd@z Thu Jan  1 00:00:00 1970
From: greg@kroah.com (Greg KH)
Date: Sat, 10 Sep 2016 17:14:12 +0200
Subject: Extend device driver?
In-Reply-To: <nr162s$m4b$1@blaine.gmane.org>
References: <nr162s$m4b$1@blaine.gmane.org>
Message-ID: <20160910151412.GA9954@kroah.com>
To: kernelnewbies@lists.kernelnewbies.org
List-Id: kernelnewbies.lists.kernelnewbies.org

On Sat, Sep 10, 2016 at 04:41:34PM +0200, Pol Eyschen wrote:
> Hi everyone,
> 
> I want to implement some custom functions of my mouse (Madcatz RAT5) in 
> Linux, e.g custom DPI-values. As this requires writing over USB to the 
> firmware of the mouse I was thinking of writing a module to accomplish 
> this. However I don't want to reimplement a whole mouse-driver,so I 
> wanted to ask if there is a possibility of binding the device to 2 
> modules or having my module extend usbhid, so that my module would only 
> be used to perform these custom operations while usbhid stays in charge 
> of the whole "mouse business".

Please just use the hidraw userspace driver/library instead, that way
you don't have to unbind the kernel driver and everything should work
just fine without having to touch the kernel at all.

Hope this helps,

greg k-h