[PATCH 0/4] Socfpga: clk: trivial fixes and cleanup

[dinguyen@altera.com (Dinh Nguyen)]

Hi Steffen,

On Tue, 2013-11-19 at 09:14 +0100, Steffen Trumtrar wrote:
> Hi Dinh!
> 
> On Mon, Nov 18, 2013 at 11:11:52AM -0600, Dinh Nguyen wrote:
> > Hi Steffen,
> > 
> > 
> > On Tue, Nov 12, 2013 at 1:40 AM, Steffen Trumtrar <s.trumtrar@pengutronix.de
> > > wrote:
> > > I actually also wanted to change the l3_sp_clk, as it seems to be neglect
> > > the "1 or 2" divider from l3_mp_clk IIRC, but I couldn't come up with a
> > > good
> > > way without changing the binding or something. What do you thing about
> > > that?
> > > Is that wrong at the moment or do I miss something?
> > >
> > 
> > Ah yes, the l3_sp_clk's parent should be l3_mp_clk and not mainclk.
> > 
> > Thanks for spotting that...
> > 
> > Dinh
> > 
> 
> Hm, that doesn't sound right. Don't we currently have Gate+Divider combo in
> the l3_mp_clk? If you turn off the clock gate from the l3_mp_clk, then l3_sp_clk
> would also be turned off.
> But according to Figure 2-3 in cv_5v4.pdf
> 
> 	DIV1 --------> GATE -----> L3_MP_CLK
>                  |
> 		 |---- DIV2 -----> L3_SP_CLK
> 
> So, l3_sp_clk's parent is the divider of l3_mp_clk but NOT the gate.

I just doubled checked. The L3_SP_CLK is taken before the gate of the
L3_MP_CLK, so turning off the L3_MP_CLK does not turn off the L3_SP_CLK.
So with this information, I think the parent for the L3_SP_CLK can be
the L3_MP_CLK, so that the extra divider is accounted for.

Dinh
> 
> Regards,
> Steffen
>