Messages in this thread | | | From | Jernej Škrabec <> | Subject | Re: [PATCH v5 05/11] clk: sunxi-ng: Add helper function to find closest rate | Date | Sun, 06 Aug 2023 15:41:48 +0200 |
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Dne nedelja, 06. avgust 2023 ob 15:06:50 CEST je Frank Oltmanns napisal(a): > The default behaviour of clocks in the sunxi-ng driver is to select a > clock rate that is closest to but less than the requested rate. > > Add the ccu_is_better_rate() helper function that - depending on the > fact if thc CCU_FEATURE_CLOSEST_RATE flag is set - decides if a rate is > closer than another rate. > > Acked-by: Maxime Ripard <mripard@kernel.org> > Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Best regards, Jernej
> --- > drivers/clk/sunxi-ng/ccu_common.c | 12 ++++++++++++ > drivers/clk/sunxi-ng/ccu_common.h | 5 +++++ > 2 files changed, 17 insertions(+) > > diff --git a/drivers/clk/sunxi-ng/ccu_common.c > b/drivers/clk/sunxi-ng/ccu_common.c index 8d28a7a079d0..8babce55302f 100644 > --- a/drivers/clk/sunxi-ng/ccu_common.c > +++ b/drivers/clk/sunxi-ng/ccu_common.c > @@ -39,6 +39,18 @@ void ccu_helper_wait_for_lock(struct ccu_common *common, > u32 lock) } > EXPORT_SYMBOL_NS_GPL(ccu_helper_wait_for_lock, SUNXI_CCU); > > +bool ccu_is_better_rate(struct ccu_common *common, > + unsigned long target_rate, > + unsigned long current_rate, > + unsigned long best_rate) > +{ > + if (common->features & CCU_FEATURE_CLOSEST_RATE) > + return abs(current_rate - target_rate) < abs(best_rate - target_rate); > + > + return current_rate <= target_rate && current_rate > best_rate; > +} > +EXPORT_SYMBOL_NS_GPL(ccu_is_better_rate, SUNXI_CCU); > + > /* > * This clock notifier is called when the frequency of a PLL clock is > * changed. In common PLL designs, changes to the dividers take effect > diff --git a/drivers/clk/sunxi-ng/ccu_common.h > b/drivers/clk/sunxi-ng/ccu_common.h index 5ad219f041d5..942a72c09437 100644 > --- a/drivers/clk/sunxi-ng/ccu_common.h > +++ b/drivers/clk/sunxi-ng/ccu_common.h > @@ -53,6 +53,11 @@ struct sunxi_ccu_desc { > > void ccu_helper_wait_for_lock(struct ccu_common *common, u32 lock); > > +bool ccu_is_better_rate(struct ccu_common *common, > + unsigned long target_rate, > + unsigned long current_rate, > + unsigned long best_rate); > + > struct ccu_pll_nb { > struct notifier_block clk_nb; > struct ccu_common *common;
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