clk: scmi: Fix clock rate rounding

[ Upstream commit d0c81a3 ]

While the do_div() helper used for rounding expects its divisor argument
to be a 32bits quantity, the currently provided divisor parameter is a
64bit value that, as a consequence, is silently truncated and a possible
source of bugs.

Fix by using the proper div64_ul helper.

Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-clk@vger.kernel.org
Fixes: 7a8655e ("clk: scmi: Fix the rounding of clock rate")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260508153300.2224715-2-cristian.marussi@arm.com
Reviewed-by: Brian Masney <bmasney@redhat.com>
Signed-off-by: Sudeep Holla <sudeep.holla@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: cris-ma

drivers/clk/clk-scmi.c

@@ -9,9 +9,9 @@
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/of.h>
+#include <linux/math64.h>
 #include <linux/module.h>
 #include <linux/scmi_protocol.h>
-#include <asm/div64.h>
 
 static const struct scmi_clk_proto_ops *scmi_proto_clk_ops;
 
@@ -61,7 +61,7 @@ static long scmi_clk_round_rate(struct clk_hw *hw, unsigned long rate,
 
 	ftmp = rate - fmin;
 	ftmp += clk->info->range.step_size - 1; /* to round up */
-	do_div(ftmp, clk->info->range.step_size);
+	ftmp = div64_ul(ftmp, clk->info->range.step_size);
 
 	return ftmp * clk->info->range.step_size + fmin;
 }