[PATCH 1/3] clk: socfpga: Fix integer overflow in clock calculation

[mturquette@linaro.org (Mike Turquette)]

Quoting Dinh Nguyen (2014-02-26 07:33:06)
> On Wed, 2014-02-26 at 00:37 -0800, Mike Turquette wrote:
> > Quoting dinguyen at altera.com (2014-02-19 13:11:10)
> > > From: Dinh Nguyen <dinguyen@altera.com>
> > > 
> > > Use 64-bit integer for calculating clock rate. Also use do_div for the
> > > 64-bit division.
> > > 
> > > Signed-off-by: Graham Moore <grmoore@altera.com>
> > > Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
> > > Cc: Mike Turquette <mturquette@linaro.org>
> > > Cc: Steffen Trumtrar <s.trumtrar@pengutronix.de>
> > 
> > Changes to the clk driver look good to me.
> > 
> 
> Can you apply the first 2 patches to your tree? I'll send the 3rd dts
> patch through the arm-soc tree.

Done!

Regards,
Mike

> 
> Thanks alot...
> Dinh
> > Regards,
> > Mike
> > 
> > > ---
> > >  drivers/clk/socfpga/clk-pll.c |    8 +++++---
> > >  1 file changed, 5 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/drivers/clk/socfpga/clk-pll.c b/drivers/clk/socfpga/clk-pll.c
> > > index 362004e..834b6e9 100644
> > > --- a/drivers/clk/socfpga/clk-pll.c
> > > +++ b/drivers/clk/socfpga/clk-pll.c
> > > @@ -44,7 +44,8 @@ static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
> > >                                          unsigned long parent_rate)
> > >  {
> > >         struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
> > > -       unsigned long divf, divq, vco_freq, reg;
> > > +       unsigned long divf, divq, reg;
> > > +       unsigned long long vco_freq;
> > >         unsigned long bypass;
> > >  
> > >         reg = readl(socfpgaclk->hw.reg);
> > > @@ -54,8 +55,9 @@ static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
> > >  
> > >         divf = (reg & SOCFPGA_PLL_DIVF_MASK) >> SOCFPGA_PLL_DIVF_SHIFT;
> > >         divq = (reg & SOCFPGA_PLL_DIVQ_MASK) >> SOCFPGA_PLL_DIVQ_SHIFT;
> > > -       vco_freq = parent_rate * (divf + 1);
> > > -       return vco_freq / (1 + divq);
> > > +       vco_freq = (unsigned long long)parent_rate * (divf + 1);
> > > +       do_div(vco_freq, (1 + divq));
> > > +       return (unsigned long)vco_freq;
> > >  }
> > >  
> > >  static struct clk_ops clk_pll_ops = {
> > > -- 
> > > 1.7.9.5
> > > 
> 
>