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Message-ID: <20130610221605.8816.20262@quantum>
Date: Mon, 10 Jun 2013 15:16:05 -0700
From: Mike Turquette <mturquette@...aro.org>
To: Kukjin Kim <kgene.kim@...sung.com>,
'Doug Anderson' <dianders@...omium.org>
Cc: 'Tomasz Figa' <tomasz.figa@...il.com>,
'Thomas Abraham' <thomas.abraham@...aro.org>,
'Olof Johansson' <olof@...om.net>,
'Vikas Sajjan' <vikas.sajjan@...aro.org>,
'Yadwinder Singh Brar' <yadi.brar01@...il.com>,
'linux-samsung-soc' <linux-samsung-soc@...r.kernel.org>,
'Tomasz Figa' <t.figa@...sung.com>,
linux-kernel@...r.kernel.org
Subject: Re: RE: [PATCH] clk: samsung: Fix pll36xx_recalc_rate to handle kdiv properly
Quoting Kukjin Kim (2013-06-05 04:51:29)
> Doug Anderson wrote:
> >
> > The KDIV value is often listed as unsigned but it needs to be treated
> > as a 16-bit signed value when using it in calculations. Fix our rate
> > recalculation to do this correctly.
> >
> > Before doing this, I tried setting EPLL on exynos5250 to:
> > rate, m, p, s, k = 80000000, 107, 2, 4, 43691
> >
> > This rate is exactly from the table in the exynos5250 user manual.
> >
> > I read this back as 80750003 with:
> > cat /sys/kernel/debug/clk/fin_pll/fout_epll/clk_rate
> >
> > After this patch, it reads back as 80000003
> >
> > mw 0x10020130 a06b0204
> > mw 0x10020134 0000aaab
> >
> > Signed-off-by: Doug Anderson <dianders@...omium.org>
>
> Yeah,
>
> Acked-by: Kukjin Kim <kgene.kim@...sung.com>
>
> Mike, please apply in your fixes.
>
> Thanks.
>
> - Kukjin
>
> > ---
> > This patch is based upon another in-flight patch to avoid conflicts:
> > clk: samsung: Use clk->base instead of directly using clk->con0 for
> > PLL3xxx
> > https://patchwork.kernel.org/patch/2629751/
The dependency series is not destined for clk-fixes but Kukjin has
requested this patch as a fix. If you want this patch as a fix can you
rebase it against:
git://git.linaro.org/people/mturquette/linux.git clk-fixes
Thanks,
Mike
> >
> > drivers/clk/samsung/clk-pll.c | 5 +++--
> > 1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/clk/samsung/clk-pll.c b/drivers/clk/samsung/clk-pll.c
> > index 01f17cf..26416bb 100644
> > --- a/drivers/clk/samsung/clk-pll.c
> > +++ b/drivers/clk/samsung/clk-pll.c
> > @@ -115,7 +115,8 @@ static unsigned long
> > samsung_pll36xx_recalc_rate(struct clk_hw *hw,
> > unsigned long parent_rate)
> > {
> > struct samsung_clk_pll *pll = to_clk_pll(hw);
> > - u32 mdiv, pdiv, sdiv, kdiv, pll_con0, pll_con1;
> > + u32 mdiv, pdiv, sdiv, pll_con0, pll_con1;
> > + s16 kdiv;
> > u64 fvco = parent_rate;
> >
> > pll_con0 = pll_readl(pll, PLL36XX_CON0_OFFSET);
> > @@ -123,7 +124,7 @@ static unsigned long
> > samsung_pll36xx_recalc_rate(struct clk_hw *hw,
> > mdiv = (pll_con0 >> PLL36XX_MDIV_SHIFT) & PLL36XX_MDIV_MASK;
> > pdiv = (pll_con0 >> PLL36XX_PDIV_SHIFT) & PLL36XX_PDIV_MASK;
> > sdiv = (pll_con0 >> PLL36XX_SDIV_SHIFT) & PLL36XX_SDIV_MASK;
> > - kdiv = pll_con1 & PLL36XX_KDIV_MASK;
> > + kdiv = (s16)(pll_con1 & PLL36XX_KDIV_MASK);
> >
> > fvco *= (mdiv << 16) + kdiv;
> > do_div(fvco, (pdiv << sdiv));
> > --
> > 1.8.2.1
--
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