|| ||Andy Green <andy-AT-warmcat.com> |
|| ||Linux USB list <linux-usb-AT-vger.kernel.org> |
|| ||RFC: Platform data for onboard USB assets |
|| ||Fri, 11 Mar 2011 09:50:32 +0000|
|| ||lkml <linux-kernel-AT-vger.kernel.org>|
|| ||Article, Thread
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
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
Comments, implementation suggestions, enquiries as to my level of crack
consumption etc welcomed ^^
to post comments)