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

[Jerome Brunet <jbrunet@baylibre.com>]

On mer. 22 juil. 2026 at 23:40, Chen-Yu Tsai <wens@kernel.org> wrote:

> On Wed, Jul 22, 2026 at 10:48 PM Jerome Brunet <jbrunet@baylibre.com> 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@kernel.org>
>> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
>> ---
>>  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?
>

Argh indeed, that's no longer necessary 

>
>>  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
>>

-- 
Jerome