Re: [RFC][PATCH 1/2] ARM: OMAP4: clock: Add device tree support forAUXCLKs

From: Nishanth Menon
Date: Tue Apr 09 2013 - 16:49:34 EST


On 10:43-20130409, Tony Lindgren wrote:
> * Tony Lindgren <tony@xxxxxxxxxxx> [130409 09:54]:
> > * Roger Quadros <rogerq@xxxxxx> [130409 03:00]:
> > > On 04/05/2013 06:58 PM, Tony Lindgren wrote:
> > > >
> > > > Can't you just use the clock name there to get it?
> > >
> > > In device tree we don't pass around clock names. You can either get
> > > a phandle or an index to the clock.
> > >
> > > e.g. Documentation/devicetree/bindings/clock/imx31-clock.txt
> >
> > Yes I understand that. But the driver/clock/omap driver can just
> > remap the DT device initially so the board specific clock is
> > found from the clock alias table. Basically initially a passthrough
> > driver that can be enhanced to parse DT clock bindings and load
> > data from /lib/firmware.
>
> Actually probably the driver/clock/omap can even do even less
> initially. There probably even no need to remap clocks there.
>
> As long as the DT clock driver understands that a board specific
> auxclk is specified in the DT it can just call clk_add_alias() so
> the driver will get the right auxclk from cclock44xx_data.c.
>
> Then other features can be added later on like to allocate a
> clock entirely based on the binding etc.
I did try to have an implementation for cpufreq using clock nodes.
unfortunately, device tree wont let me have arguments of strings :(
So, I am unable to do clock = <&clk mpu_dpll>;
instead, I am forced to do clock = <&clk 249>;

Here is an attempt on beagleXM - adds every clock node to the list.
Tons of un-necessary prints added to give an idea - see log:
http://pastebin.com/F9A2zSTr

Would an cleaned up version be good enough as a step #1 of transition?