[ECOS] USB slave device on ecos

Bart Veer bartv@ecoscentric.com
Tue Apr 22 10:25:00 GMT 2003


>>>>> "Charles-Henri" == Charles-Henri Balet <charles-henri@bluewin.ch> writes:

    Charles-Henri> Hello,
    Charles-Henri> I want to use on my EDB7312 of cirrus the USB port
    Charles-Henri> on ecos, the usb chip is the Philips PDIUSBD12, any
    Charles-Henri> has used it ? if not how can I modify an existing
    Charles-Henri> driver for this chip ?

I am not aware of an existing eCos USB driver for the PDIUSBD12.
Writing USB drivers is non-trivial, so if you have not done USB work
before I suggest some background reading first. Hyde's "USB Design by
Example" is an easy read, and I have also heard good things about
Axelson's "USB Complete". You will also need the standard documents
from www.usb.org - go to the Developers section, Documents, and
download the 2.0 or 1.1 specs.

For information about the eCos USB support see
http://sources.redhat.com/ecos/docs-latest/ref/io-usb-slave.html
and
http://sources.redhat.com/ecos/docs-latest/ref/usbs-writing.html

There should be example code available from Philips, which will prove
very useful. I believe the Philips part is rather more reliable than
the devices used for the existing eCos drivers - the SA1110 USB
support in particular was only borderline functional, at best. Hence
writing a suitable driver should be easier, but still not trivial.

It is likely that you will need access to a USB protocol analyser at
some stage during the development. Without such hardware there is no
easy way of seeing exactly what bytes are going over the wires, making
debugging much more difficult. The analysers produced by CATC are
good, albeit expensive.

Bart

-- 
Bart Veer                       eCos Configuration Architect
http://www.ecoscentric.com/     The eCos and RedBoot experts

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