| Message ID | 20230717-pll-mipi_set_rate_parent-v4-6-04acf1d39765@oltmanns.dev (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | clk: sunxi-ng: Consider alternative parent rates when determining NKM clock rate | expand |
On Mon, 17 Jul 2023 15:34:30 +0200, Frank Oltmanns wrote: > 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 > > [ ... ] Acked-by: Maxime Ripard <mripard@kernel.org> Thanks! Maxime
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;
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. 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(+)