[PATCH] clk: clocking-wizard: Fix overflow in clockout0 divisor calculation

[PATCH] clk: clocking-wizard: Fix overflow in clockout0 divisor calculation

[shaopeijie]

From: Peijie Shao <shaopeijie@gmail.com>

On 32-bit platforms (e.g., Zynq 7000 series), parent_rate * 1000
may overflow, leading to incorrect divisor calculation.

The issue was first found on Zynq7020 with "parent_rate=1GHz"
and "xlnx,nr-outputs=2".

Cast parent_rate to u64 and use the ULL version of DIV_ROUND*
instead.

Signed-off-by: Peijie Shao <shaopeijie@gmail.com>
---
 drivers/clk/xilinx/clk-xlnx-clock-wizard.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/xilinx/clk-xlnx-clock-wizard.c b/drivers/clk/xilinx/clk-xlnx-clock-wizard.c
index edf8c0eaca27..5abbc6b83b72 100644
--- a/drivers/clk/xilinx/clk-xlnx-clock-wizard.c
+++ b/drivers/clk/xilinx/clk-xlnx-clock-wizard.c
@@ -881,10 +881,10 @@ static int clk_wzrd_dynamic_reconfig_f(struct clk_hw *hw, unsigned long rate,
 	struct clk_wzrd_divider *divider = to_clk_wzrd_divider(hw);
 	void __iomem *div_addr = divider->base + divider->offset;
 
-	rate_div = DIV_ROUND_DOWN_ULL(parent_rate * 1000, rate);
+	rate_div = DIV_ROUND_DOWN_ULL((u64)parent_rate * 1000, rate);
 	clockout0_div = rate_div / 1000;
 
-	pre = DIV_ROUND_CLOSEST((parent_rate * 1000), rate);
+	pre = DIV_ROUND_CLOSEST_ULL((u64)parent_rate * 1000, rate);
 	f = (u32)(pre - (clockout0_div * 1000));
 	f = f & WZRD_CLKOUT_FRAC_MASK;
 	f = f << WZRD_CLKOUT_DIVIDE_WIDTH;
-- 
2.43.5