Messages in this thread Patch in this message | | | From | Frank Oltmanns <> | Date | Sun, 06 Aug 2023 15:06:50 +0200 | Subject | [PATCH v5 05/11] clk: sunxi-ng: Add helper function to find closest rate |
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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> --- 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; -- 2.41.0
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