From: Maxime Ripard Date: Fri, 5 May 2023 11:25:39 +0000 (+0200) Subject: clk: ux500: prcmu: Add a determine_rate hook X-Git-Tag: microblaze-v6.6~61^2~4^3~34 X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=97eb8f8a95fac869f3ffc75cda0308ab07780f4f;p=linux-2.6-microblaze.git clk: ux500: prcmu: Add a determine_rate hook The UX500 PRCMU "clkout" clock implements a mux with a set_parent hook, but doesn't provide a determine_rate implementation. This is a bit odd, since set_parent() is there to, as its name implies, change the parent of a clock. However, the most likely candidates to trigger that parent change are either the assigned-clock-parents device tree property or a call to clk_set_rate(), with determine_rate() figuring out which parent is the best suited for a given rate. The PRCMU binding also allows to specify the default clock parent through a device tree cell. This will be enforced at prepare time by the driver. The other trigger would be a call to clk_set_parent(), but it's far less used, and it doesn't look like there's any obvious user for that clock. The result is that the driver relies on prepare to set the default parent, and thus the set_parent hook is effectively unused by design. We can make that decision explicit by setting the determine_rate implementation to clk_hw_determine_rate_no_reparent() that will keep the same behaviour. Indeed, if no determine_rate implementation is provided, clk_round_rate() (through clk_core_round_rate_nolock()) will call itself on the parent if CLK_SET_RATE_PARENT is set, and will not change the clock rate otherwise. Cc: Ulf Hansson Cc: linux-arm-kernel@lists.infradead.org Acked-by: Linus Walleij Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20221018-clk-range-checks-fixes-v4-37-971d5077e7d2@cerno.tech Signed-off-by: Stephen Boyd --- diff --git a/drivers/clk/ux500/clk-prcmu.c b/drivers/clk/ux500/clk-prcmu.c index 4deb37f19a7c..5cbf24c94606 100644 --- a/drivers/clk/ux500/clk-prcmu.c +++ b/drivers/clk/ux500/clk-prcmu.c @@ -344,6 +344,7 @@ static const struct clk_ops clk_prcmu_clkout_ops = { .prepare = clk_prcmu_clkout_prepare, .unprepare = clk_prcmu_clkout_unprepare, .recalc_rate = clk_prcmu_clkout_recalc_rate, + .determine_rate = clk_hw_determine_rate_no_reparent, .get_parent = clk_prcmu_clkout_get_parent, .set_parent = clk_prcmu_clkout_set_parent, };