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

Maxime Ripard
2017-06-27T09:46:07Z

[-- Attachment #1: Type: text/plain, Size: 2181 bytes --]

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-q/aMd4JkU83YtjvyW6yDsg@public.gmane.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.

> 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?

Thanks!
Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering