[PATCH 02/11] clk: scmi: Use new determine_rate clock operation

[Peng Fan]

On Fri, Feb 27, 2026 at 03:32:16PM +0000, Cristian Marussi wrote:
>Use the Clock protocol layer determine_rate logic to calculate the closest
>rate that can be supported by a specific clock.
>
>No functional change.
>
>Cc: Brian Masney <bmasney at redhat.com>
>Cc: Michael Turquette <mturquette at baylibre.com>
>Cc: Stephen Boyd <sboyd at kernel.org>
>Cc: linux-clk at vger.kernel.org
>Signed-off-by: Cristian Marussi <cristian.marussi at arm.com>
>---
>Note that the calculation logic in the protocol layer is exactly the same
>as it wes here.
>
>@Brian I suppose once your CLK_ROUNDING_FW_MANAGED sereis is merged I can flag
>such SCMI clocks.

Per my reading of Brain's thread, if ->determine_rate exists,
->determine_rate() will be used.

 	} else if (core->ops->determine_rate) {
 		return core->ops->determine_rate(core->hw, req);
+	} else if (clk_is_rounding_fw_managed(core)) {
+		return 0;

So unless update scmi_clk_determine_rate() to something:
--------
if (clk & CLK_ROUNDING_FW_MANAGED)
	return 0;

return scmi_proto_clk_ops->determine_rate(clk->ph, clk->id, &req->rate);
--------

It maybe better to update Brain's patch to move clk_is_rounding_fw_managed()
above the check of core->ops->determine_rate().

>---
> drivers/clk/clk-scmi.c | 31 ++++++-------------------------
> 1 file changed, 6 insertions(+), 25 deletions(-)
>
>diff --git a/drivers/clk/clk-scmi.c b/drivers/clk/clk-scmi.c
>index 6b286ea6f121..c223e4ef1dd1 100644
>--- a/drivers/clk/clk-scmi.c
>+++ b/drivers/clk/clk-scmi.c
>@@ -12,7 +12,6 @@
> #include <linux/of.h>
> #include <linux/module.h>
> #include <linux/scmi_protocol.h>
>-#include <asm/div64.h>
> 
> #define NOT_ATOMIC	false
> #define ATOMIC		true
>@@ -57,35 +56,17 @@ static unsigned long scmi_clk_recalc_rate(struct clk_hw *hw,
> static int scmi_clk_determine_rate(struct clk_hw *hw,
> 				   struct clk_rate_request *req)
> {
>-	u64 fmin, fmax, ftmp;
>+	int ret;
> 	struct scmi_clk *clk = to_scmi_clk(hw);
> 
> 	/*
>-	 * We can't figure out what rate it will be, so just return the
>-	 * rate back to the caller. scmi_clk_recalc_rate() will be called
>-	 * after the rate is set and we'll know what rate the clock is
>+	 * If we could not get a better rate scmi_clk_recalc_rate() will be
>+	 * called after the rate is set and we'll know what rate the clock is
> 	 * running at then.
> 	 */
>-	if (clk->info->rate_discrete)
>-		return 0;
>-
>-	fmin = clk->info->range.min_rate;
>-	fmax = clk->info->range.max_rate;
>-	if (req->rate <= fmin) {
>-		req->rate = fmin;
>-
>-		return 0;
>-	} else if (req->rate >= fmax) {
>-		req->rate = fmax;
>-
>-		return 0;
>-	}
>-
>-	ftmp = req->rate - fmin;
>-	ftmp += clk->info->range.step_size - 1; /* to round up */
>-	do_div(ftmp, clk->info->range.step_size);
>-
>-	req->rate = ftmp * clk->info->range.step_size + fmin;
>+	ret = scmi_proto_clk_ops->determine_rate(clk->ph, clk->id, &req->rate);
>+	if (ret)
>+		return ret;

nit:
"return scmi_proto_clk_ops->determine_rate(clk->ph, clk->id, &req->rate);"

Otherwise:
Reviewed-by: Peng Fan <peng.fan at nxp.com>

> 
> 	return 0;
> }
>-- 
>2.53.0
>