Date: Wed, 25 Feb 2015 19:13:12 +0900
From: Inha Song <ideal.song@samsung.com>
To: Tomasz Figa <tomasz.figa@gmail.com>
Cc: "linux-samsung-soc@vger.kernel.org" 
	<linux-samsung-soc@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        Kukjin Kim <kgene@kernel.org>, Stephen Boyd <sboyd@codeaurora.org>,
        Michael Turquette <mturquette@linaro.org>,
        Sylwester Nawrocki <s.nawrocki@samsung.com>,
        Chanwoo Choi <cw00.choi@samsung.com>
Subject: Re: [PATCH] clk: samsung: Add CLKOUT driver support for Exynos3250 SoC.
Message-id: <20150225191312.303ba10d@songinha-Samsung-DeskTop-System>
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Hi, Tomasz,

Thanks for you comment :)

On Wed, 25 Feb 2015 09:54:02 +0900
Tomasz Figa <tomasz.figa@gmail.com> wrote:

> Hi Inha,
> 
> Thanks for the patch. Please see my comments inline.
> 
> 2015-02-24 18:22 GMT+09:00 Inha Song <ideal.song@samsung.com>:
> > This patch add CLKOUT driver support for Exynos3250 SoC.
> 
> Could you please add a little more information? I know that it might
> be pretty obvious to people familiar with this driver and/or hardware,
> but it might be a good idea to explicitly say that the CLKOUT
> controller is compatible with Exynos4, so only a new compatible string
> is added.
> 
> On the other hand, do you really need to add a new compatible string
> if an existing one can be reused? The reason why the DT property is
> called "compatible" is to be able to use the same compatible strings
> on different devices, because they are compatible, even though the
> string might have its name after only one of them. If there is some
> additional reason to add a new compatible string, please write this in
> commit message.

In in PMU document(Document/devicetree/bindgins/arm/samsung/pmu.txt),
"samsung,exynos3250-pmu" compatible string had been added.

So I add this compatible in driver.

> 
> >
> > Signed-off-by: Inha Song <ideal.song@samsung.com>
> > ---
> >  drivers/clk/samsung/clk-exynos-clkout.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/clk/samsung/clk-exynos-clkout.c b/drivers/clk/samsung/clk-exynos-clkout.c
> > index 3a7cb25..1c02e73 100644
> > --- a/drivers/clk/samsung/clk-exynos-clkout.c
> > +++ b/drivers/clk/samsung/clk-exynos-clkout.c
> > @@ -142,6 +142,8 @@ CLK_OF_DECLARE(exynos4212_clkout, "samsung,exynos4212-pmu",
> >                 exynos4_clkout_init);
> >  CLK_OF_DECLARE(exynos4412_clkout, "samsung,exynos4412-pmu",
> >                 exynos4_clkout_init);
> > +CLK_OF_DECLARE(exynos3250_clkout, "samsung,exynos3250-pmu",
> > +               exynos4_clkout_init);
> 
> Are you sure that the PMU DEBUG register on Exynos3250 is indeed
> compatible with Exynos4 and not with newer SoCs? AFAIR, the only
> difference was the number of bits (4 on Exynos4 and 5 on Exynos5?) of
> the main mux.

Exynos3250 PMU_DEBUG register is same with Exynos4. So I just use exynos4_clkout_init function.
But, on second thought, It looks good to add exynos3_clkout_init function for Exynos3 SoC even though it's the same with exynos4_clkout_init.

what is your opinion?

Best Regards,
Inha Song.

> 
> Best regards,
> Tomasz
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