[PATCH v3 6/8] clk: sunxi-ng: mux: Support finding closest rate
Maxime Ripard
maxime at cerno.tech
Mon Jul 3 00:38:48 PDT 2023
On Sun, Jul 02, 2023 at 07:55:25PM +0200, Frank Oltmanns wrote:
> When finding the best rate for a mux clock, consider rates that are
> higher than the requested rate by introducing a new clk_ops structure
> that uses the existing __clk_mux_determine_rate_closest function.
> Furthermore introduce an initialization macro that uses this new
> structure.
>
> Signed-off-by: Frank Oltmanns <frank at oltmanns.dev>
> ---
> drivers/clk/sunxi-ng/ccu_mux.c | 13 +++++++++++++
> drivers/clk/sunxi-ng/ccu_mux.h | 17 +++++++++++++++++
> 2 files changed, 30 insertions(+)
>
> diff --git a/drivers/clk/sunxi-ng/ccu_mux.c b/drivers/clk/sunxi-ng/ccu_mux.c
> index 8594d6a4addd..49a592bdeacf 100644
> --- a/drivers/clk/sunxi-ng/ccu_mux.c
> +++ b/drivers/clk/sunxi-ng/ccu_mux.c
> @@ -264,6 +264,19 @@ static unsigned long ccu_mux_recalc_rate(struct clk_hw *hw,
> parent_rate);
> }
>
> +const struct clk_ops ccu_mux_closest_ops = {
> + .disable = ccu_mux_disable,
> + .enable = ccu_mux_enable,
> + .is_enabled = ccu_mux_is_enabled,
> +
> + .get_parent = ccu_mux_get_parent,
> + .set_parent = ccu_mux_set_parent,
> +
> + .determine_rate = __clk_mux_determine_rate_closest,
> + .recalc_rate = ccu_mux_recalc_rate,
> +};
> +EXPORT_SYMBOL_NS_GPL(ccu_mux_closest_ops, SUNXI_CCU);
> +
This is also a bit inconsistent with the other clocks: most (all?) of
them will simply handle this through a flag, but this one requires a new
set of clk_ops as well?
I think we should create our own wrapper here around
__clk_mux_determine_rate and either call
__clk_mux_determine_rate_closest or __clk_mux_determine_rate depending
on the state of the flags, or call __clk_mux_determine_rate_flags with
the proper flags set for our clock.
The former is probably slightly simpler.
> const struct clk_ops ccu_mux_ops = {
> .disable = ccu_mux_disable,
> .enable = ccu_mux_enable,
> diff --git a/drivers/clk/sunxi-ng/ccu_mux.h b/drivers/clk/sunxi-ng/ccu_mux.h
> index 2c1811a445b0..c4ee14e43719 100644
> --- a/drivers/clk/sunxi-ng/ccu_mux.h
> +++ b/drivers/clk/sunxi-ng/ccu_mux.h
> @@ -46,6 +46,22 @@ struct ccu_mux {
> struct ccu_common common;
> };
>
> +#define SUNXI_CCU_MUX_TABLE_WITH_GATE_CLOSEST(_struct, _name, _parents, _table, \
> + _reg, _shift, _width, _gate, \
> + _flags) \
> + struct ccu_mux _struct = { \
> + .enable = _gate, \
> + .mux = _SUNXI_CCU_MUX_TABLE(_shift, _width, _table), \
> + .common = { \
> + .reg = _reg, \
> + .hw.init = CLK_HW_INIT_PARENTS(_name, \
> + _parents, \
> + &ccu_mux_closest_ops, \
> + _flags), \
> + .features = CCU_FEATURE_CLOSEST_RATE, \
> + } \
> + }
> +
I'm fine with that one, but like we discussed on the NM (I think?) patch
already, this creates some clocks and macros that will use the feature
as a flag, and some will encode it into their name.
Given that we need it here too, I'm really inclined to prefer what you
did there, and thus create a new macro for pll-video0 instead of
modifying the existing one.
Maxime
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