RFC: Platform data for onboard USB assets
[Posted March 29, 2011 by corbet]
| From: |
| Andy Green <andy-AT-warmcat.com> |
| To: |
| Linux USB list <linux-usb-AT-vger.kernel.org> |
| Subject: |
| RFC: Platform data for onboard USB assets |
| Date: |
| Fri, 11 Mar 2011 09:50:32 +0000 |
| Message-ID: |
| <4D79F068.2080009@linaro.org> |
| Cc: |
| lkml <linux-kernel-AT-vger.kernel.org> |
| Archive-link: |
| Article, Thread
|
Hi -
platform_data is a well established way in Linux to pass configuration
data up to on-board assets from a machine file like mach-xyz.c. It's
also supported to pass platform_data up to devices that are probed
asynchronously from busses like i2c as well, which is very handy.
However AFAIK it's not possible to bind platform_data to probed USB
devices as it stands.
There are now boards which have on-board USB assets, for example OMAP4
Panda which has a USB <-> Ethernet bridge wired up permanently. It'd be
convenient to also be able to pass optional platform_data to these
devices when they are asynchronously probed.
So what's the feeling about a new api to register an array of
platform_data pointers bound to static "devpath" names in the machine file?
When a usb device is instantiated, it can check through this array if it
exists, matching on devname, and attach the platform_data to the
underlying probed usb device's dev->platform_data, which it seems is
currently unused.
The particular use that suggested this is on Panda, it would be ideal to
be able to set a flag in the usb device's platform data that forces it
to be named eth%d since it's a hardwired asset on the board with an RJ45
socket.
Comments, implementation suggestions, enquiries as to my level of crack
consumption etc welcomed ^^
-Andy
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