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

Tony Lindgren tony at atomide.com
Wed Mar 5 12:21:56 EST 2014


* Christoph Fritz <chf.fritz at googlemail.com> [140305 05:28]:
> 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
> here.
> 
> So in my view, a driver is unnecessary.

Yeah that makes sense. Let's try not to rely on pdata-quirks.c for
the new boards.

Regards,

Tony



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