Re: [PATCH v4 1/6] clk: sunxi-ng: div: Add support for fixed post-divider

Priit Laes
2017-06-28T17:59:49Z

On Tue, Jun 27, 2017 at 11:46:07AM +0200, Maxime Ripard wrote:
> Hi!
>
> On Sun, Jun 25, 2017 at 11:45:42PM +0300, Priit Laes wrote:
> > SATA clock on sun4i/sun7i is of type (parent) / M / 6 where
> > 6 is fixed post-divider.
> >
> > Signed-off-by: Priit Laes <plaes@plaes.org>
> > ---
> > drivers/clk/sunxi-ng/ccu_div.c | 12 ++++++++++--
> > drivers/clk/sunxi-ng/ccu_div.h | 3 ++-
> > 2 files changed, 12 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/clk/sunxi-ng/ccu_div.c b/drivers/clk/sunxi-ng/ccu_div.c
> > index c0e5c10..de30e15 100644
> > --- a/drivers/clk/sunxi-ng/ccu_div.c
> > +++ b/drivers/clk/sunxi-ng/ccu_div.c
> > @@ -62,8 +62,13 @@ static unsigned long ccu_div_recalc_rate(struct clk_hw *hw,
> > parent_rate = ccu_mux_helper_apply_prediv(&cd->common, &cd->mux, -1,
> > parent_rate);
> >
> > - return divider_recalc_rate(hw, parent_rate, val, cd->div.table,
> > - cd->div.flags);
> > + val = divider_recalc_rate(hw, parent_rate, val, cd->div.table,
> > + cd->div.flags);
> > +
> > + if (cd->common.features & CCU_FEATURE_FIXED_POSTDIV)
> > + val /= cd->fixed_post_div;
> > +
> > + return val;
> > }
> >
> > static int ccu_div_determine_rate(struct clk_hw *hw,
> > @@ -89,6 +94,9 @@ static int ccu_div_set_rate(struct clk_hw *hw, unsigned long rate,
> > val = divider_get_val(rate, parent_rate, cd->div.table, cd->div.width,
> > cd->div.flags);
> >
> > + if (cd->common.features & CCU_FEATURE_FIXED_POSTDIV)
> > + val *= cd->fixed_post_div;
> > +
> > spin_lock_irqsave(cd->common.lock, flags);
> >
> > reg = readl(cd->common.base + cd->common.reg);
>
> You also need to adjust the round rate call back to take into account
> the post divider before calling divider_round_rate_parent, and after
> since that function can modify the parent_rate.

Is there a way to trigger this function? I don't see it getting called.

> > diff --git a/drivers/clk/sunxi-ng/ccu_div.h b/drivers/clk/sunxi-ng/ccu_div.h
> > index 08d0744..f3a5028 100644
> > --- a/drivers/clk/sunxi-ng/ccu_div.h
> > +++ b/drivers/clk/sunxi-ng/ccu_div.h
> > @@ -86,9 +86,10 @@ struct ccu_div_internal {
> > struct ccu_div {
> > u32 enable;
> >
> > - struct ccu_div_internal div;
> > + struct ccu_div_internal div;
>
> Spurious change?

Nope, it was not indented the same way as other variables.
Should I send it as separate patch?

>
> Thanks!
> Maxime
>
> --
> Maxime Ripard, Free Electrons
> Embedded Linux and Kernel engineering
> http://free-electrons.com