[PATCH v4 4/4] ARM: OMAP2+: Add pdata quirk for sys_clkout2 for omap3 DBB056

Christoph Fritz chf.fritz at googlemail.com
Wed Mar 5 08:25:32 EST 2014

On Wed, 2014-03-05 at 15:07 +0200, Tero Kristo wrote:
> On 03/01/2014 12:37 AM, Tony Lindgren wrote:
> > * Christoph Fritz <chf.fritz at googlemail.com> [140214 06:24]:
> >> Full device tree support for clock control, especially to set frequencies,
> >> is not yet accomplished. Until then, configure the 24Mhz of sys_clkout2 to
> >> feed an USB-Hub here.
> >
> > Hmm would like to see Tero's comments on this, I wonder if we should
> > wait on this to avoid extra churn?
> Well, the set I posted that adds default clock parenting / default rate 
> support to DT hasn't actually moved forward, so you might want to take 
> this in as is now if it should be rushed. The clk-enable part isn't done 
> currently by anything anyway. Just wondering though, should you create 
> some sort of driver for your usb-hub which would control these clocks?

The USB-Hub, a USB2512 is wired as non-configurable. Its pin
'XTAL1/CLKIN' can be connected to either a crystal or an external clock
input. To economise the crystal, the clock-out of the omap is wired

So in my view, a driver is unnecessary.

  -- Christoph

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