Re: [PATCH 1/2 v2] at91/USB: Add USB drivers for at91sam9g45 series

[David Brownell <david-b@pacbell.net>]

On Thursday 11 June 2009, Nicolas Ferre wrote:
> Add both host and gadget USB drivers for at91sam9g45 series. Those SOC embed
> high speed USB interfaces.
> The gadget driver is the already available atmel_usba_udc.
> The host driver is an EHCI with its companion OHCI. EHCI is handled by the new
> ehci-atmel.c whereas the OHCI is always handled by ohci-at91.c. This last
> wrapper is modified to allow IRQ sharing between two controllers.
> 
> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

Talking only about the EHCI bits here ... it looks pretty generic
except for the clock management, which can't be.

The tricky bits here will be system suspend/resume support, with
the host controller able to trigger remote wakeup.  Clearly you
don't support system suspend/resume yet.

A slightly less tricky bit would be suspending the root hub.
Sometimes the hardware needs help there; other times it can
automatically gate the various clocks and save power.

If you split out patches for each of the drivers, I can ack
each of those seaprately.  And then hope to see patches which
add power management support before too long.

- Dave