Re: [PATCH v6 2/4] clk: sunxi-ng: div: add read-only operation support

[Chen-Yu Tsai]

On Wed, Jul 22, 2026 at 10:48 PM Jerome Brunet <jbrunet@xxxxxxxxxxxx> wrote:
>
> Add support for sunxi-ng read-only dividers. This will be
> useful to the a733 oscillator detection logic.
>
> Reviewed-by: Chen-Yu Tsai <wens@xxxxxxxxxx>
> Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
> ---
>  drivers/clk/sunxi-ng/ccu_div.c | 31 +++++++++++++++++++++++++++++--
>  drivers/clk/sunxi-ng/ccu_div.h |  1 +

>  drivers/clk/sunxi-ng/ccu_mux.c |  2 +-
>  drivers/clk/sunxi-ng/ccu_mux.h |  4 ++++

Left over stuff?


>  4 files changed, 35 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clk/sunxi-ng/ccu_div.c b/drivers/clk/sunxi-ng/ccu_div.c
> index 62d680ccb524..c385e0160f13 100644
> --- a/drivers/clk/sunxi-ng/ccu_div.c
> +++ b/drivers/clk/sunxi-ng/ccu_div.c
> @@ -20,8 +20,22 @@ static int ccu_div_determine_rate_helper(struct ccu_mux_internal *mux,
>         if (cd->common.features & CCU_FEATURE_FIXED_POSTDIV)
>                 req->rate *= cd->fixed_post_div;
>
> -       ret = divider_determine_rate(&cd->common.hw, req, cd->div.table,
> -                                    cd->div.width, cd->div.flags);
> +       if (cd->div.flags & CLK_DIVIDER_READ_ONLY) {
> +               unsigned long val;
> +               u32 reg;
> +
> +               reg = readl(cd->common.base + cd->common.reg);
> +               val = reg >> cd->div.shift;
> +               val &= (1 << cd->div.width) - 1;
> +
> +               ret = divider_ro_determine_rate(&cd->common.hw, req, cd->div.table,
> +                                               cd->div.width, cd->div.flags, val);
> +
> +       } else {
> +               ret = divider_determine_rate(&cd->common.hw, req, cd->div.table,
> +                                            cd->div.width, cd->div.flags);
> +       }
> +
>         if (ret)
>                 return ret;
>
> @@ -143,3 +157,16 @@ const struct clk_ops ccu_div_ops = {
>         .set_rate       = ccu_div_set_rate,
>  };
>  EXPORT_SYMBOL_NS_GPL(ccu_div_ops, "SUNXI_CCU");
> +
> +const struct clk_ops ccu_rodiv_ops = {
> +       .disable        = ccu_div_disable,
> +       .enable         = ccu_div_enable,
> +       .is_enabled     = ccu_div_is_enabled,
> +
> +       .get_parent     = ccu_div_get_parent,
> +       .set_parent     = ccu_div_set_parent,
> +
> +       .determine_rate = ccu_div_determine_rate,
> +       .recalc_rate    = ccu_div_recalc_rate,
> +};
> +EXPORT_SYMBOL_NS_GPL(ccu_rodiv_ops, "SUNXI_CCU");
> diff --git a/drivers/clk/sunxi-ng/ccu_div.h b/drivers/clk/sunxi-ng/ccu_div.h
> index be00b3277e97..a30a92780a05 100644
> --- a/drivers/clk/sunxi-ng/ccu_div.h
> +++ b/drivers/clk/sunxi-ng/ccu_div.h
> @@ -300,5 +300,6 @@ static inline struct ccu_div *hw_to_ccu_div(struct clk_hw *hw)
>  }
>
>  extern const struct clk_ops ccu_div_ops;
> +extern const struct clk_ops ccu_rodiv_ops;
>
>  #endif /* _CCU_DIV_H_ */
> diff --git a/drivers/clk/sunxi-ng/ccu_mux.c b/drivers/clk/sunxi-ng/ccu_mux.c
> index 4503c9780c39..12bfc99c9172 100644
> --- a/drivers/clk/sunxi-ng/ccu_mux.c
> +++ b/drivers/clk/sunxi-ng/ccu_mux.c
> @@ -67,7 +67,7 @@ unsigned long ccu_mux_helper_apply_prediv(struct ccu_common *common,
>         return parent_rate / ccu_mux_get_prediv(common, cm, parent_index);
>  }
>
> -static unsigned long ccu_mux_helper_unapply_prediv(struct ccu_common *common,
> +unsigned long ccu_mux_helper_unapply_prediv(struct ccu_common *common,
>                                             struct ccu_mux_internal *cm,
>                                             int parent_index,
>                                             unsigned long parent_rate)
> diff --git a/drivers/clk/sunxi-ng/ccu_mux.h b/drivers/clk/sunxi-ng/ccu_mux.h
> index c94a4bde5d01..272a2c36a8f2 100644
> --- a/drivers/clk/sunxi-ng/ccu_mux.h
> +++ b/drivers/clk/sunxi-ng/ccu_mux.h
> @@ -134,6 +134,10 @@ unsigned long ccu_mux_helper_apply_prediv(struct ccu_common *common,
>                                           struct ccu_mux_internal *cm,
>                                           int parent_index,
>                                           unsigned long parent_rate);
> +unsigned long ccu_mux_helper_unapply_prediv(struct ccu_common *common,
> +                                           struct ccu_mux_internal *cm,
> +                                           int parent_index,
> +                                           unsigned long parent_rate);
>  int ccu_mux_helper_determine_rate(struct ccu_common *common,
>                                   struct ccu_mux_internal *cm,
>                                   struct clk_rate_request *req,
>
> --
> 2.47.3
>