On Thu, 2014-08-28 at 05:05 -0500, Lu Jingchang-B35083 wrote:

quoted

-----Original Message-----
From: Wood Scott-B07421
Sent: Thursday, August 28, 2014 7:34 AM
To: Lu Jingchang-B35083
Cc: mturquette at linaro.org; linuxppc-dev at lists.ozlabs.org; linux-
kernel at vger.kernel.org; linux-arm-kernel at lists.infradead.org
Subject: Re: [RESEND] clk: ppc-corenet: Add Freescale ARM-based platforms
CLK_OF_DECLARE support

On Tue, 2014-08-26 at 21:19 -0500, Lu Jingchang-B35083 wrote:

quoted

quoted

-----Original Message-----
From: Wood Scott-B07421
Sent: Wednesday, August 27, 2014 6:51 AM
To: Lu Jingchang-B35083
Cc: mturquette at linaro.org; linuxppc-dev at lists.ozlabs.org; linux-
kernel at vger.kernel.org; linux-arm-kernel at lists.infradead.org
Subject: Re: [RESEND] clk: ppc-corenet: Add Freescale ARM-based
platforms CLK_OF_DECLARE support

On Fri, 2014-08-22 at 17:34 +0800, Jingchang Lu wrote:

quoted

+CLK_OF_DECLARE(ppc_core_pll_v1, "fsl,qoriq-core-pll-1.0",

core_pll_init);

quoted

+CLK_OF_DECLARE(ppc_core_pll_v2, "fsl,qoriq-core-pll-2.0",

core_pll_init);

quoted

+CLK_OF_DECLARE(ppc_core_mux_v1, "fsl,qoriq-core-mux-1.0",

core_mux_init);

quoted

+CLK_OF_DECLARE(ppc_core_mux_v2, "fsl,qoriq-core-mux-2.0",

core_mux_init);

What does this do that the existing platform driver and match table
don't?  Why is it needed for ARM when PPC didn't need it?

-Scott

Common clk init on ARM platform is initialized earlier via
of_clk_init() instead of driver probe method, the of_clk_init will
walk a __clk_of_table to init each clk provider in the table, the
CLK_OF_DECLARE() macro puts a supported clk in the __clk_of_table for it

initializing on starup, and the clk system has added some common clk such
as "fixed-clk"

quoted

to this table already.
So here I add our specific clk init declaration to consist this
framework, and the driver probe function will not be needed on ARM.

OK... Is there any reason why the new method won't work on PPC?

PPC has little dependence on the clock tree but frequency, it will work well
if adopted I think.

I'm just saying it seems redundant to have both.  Even on ARM, won't
this result in the clock getting registered twice (albeit with one of
those times being too late)?

Regardless of what dependence PPC has on the clock tree, what stops this
method of enumeration from working on PPC?  Is there anything required
other than inserting a call to of_clk_init(NULL) in the arch init code?

-Scott