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Date: Sat, 29 Dec 2007 19:53:49 -0800
From: mgross <640e9920@gmail.com>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: [RFC] USB driver for talking to the Microchip PIC18 boot loader
Message-ID: <20071230035349.GA4741@mgross-t43>
References: <20071229193409.GA20188@mgross-t43> <Pine.LNX.4.44L0.0712291714041.26261-100000@netrider.rowland.org>
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On Sat, Dec 29, 2007 at 05:15:30PM -0500, Alan Stern wrote:
> On Sat, 29 Dec 2007, mgross wrote:
> 
> > I'm playing around with a PIC based project at home (not an Intel
> > activity) and found I needed a usb driver to talk to the boot loader
> > so I can program my USB Bitwhacker with new custom firmware.  The
> > following adds the pic18bl driver to the kernel.  Its pretty simple
> > and is somewhat based on bits of a libusb driver that does some of
> > what this driver does.
> > 
> > What do you think?
> 
> Not to detract from your driver, but would it be possible to do the 
> whole thing in userspace using libusb?  Maybe by extending the driver 
> you mentioned?
>
Yeah, it has been done from user space using a libusb based
application.  (that didn't work with a usb-hub in the loop) and had
code that was just too nasty for words, so I made a kernel driver that
looks nicer to me and enables a nice python FW loader program to work.

What is the linux-usb policies on new drivers that could be
implemented in user space?  When does a kernel driver make  sense over
a libusb one?

--mgross

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