[PATCH v3 03/12] gpio: rockchip: resolve overflow issues

[Ye Zhang <ye.zhang@rock-chips.com>]

Prevent overflow issues when performing debounce-related calculations.

Fixes: 3bcbd1a85b68 ("gpio/rockchip: support next version gpio controller")
Signed-off-by: Ye Zhang <ye.zhang@rock-chips.com>
---
 drivers/gpio/gpio-rockchip.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-rockchip.c b/drivers/gpio/gpio-rockchip.c
index 5f60162baaeb..6dcb8bb0d1b4 100644
--- a/drivers/gpio/gpio-rockchip.c
+++ b/drivers/gpio/gpio-rockchip.c
@@ -22,6 +22,7 @@
 #include <linux/pinctrl/pinconf-generic.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
+#include <linux/units.h>
 
 #include "../pinctrl/core.h"
 #include "../pinctrl/pinctrl-rockchip.h"
@@ -209,11 +210,12 @@ static int rockchip_gpio_set_debounce(struct gpio_chip *gc,
 		freq = clk_get_rate(bank->db_clk);
 		if (!freq)
 			return -EINVAL;
-		max_debounce = (GENMASK(23, 0) + 1) * 2 * 1000000 / freq;
+		div = (u64)(GENMASK(23, 0) + 1) * 2 * HZ_PER_MHZ;
+		max_debounce = DIV_ROUND_CLOSEST_ULL(div, freq);
 		if (debounce > max_debounce)
 			return -EINVAL;
 
-		div = debounce * freq;
+		div = (u64)debounce * freq;
 		div_reg = DIV_ROUND_CLOSEST_ULL(div, 2 * USEC_PER_SEC) - 1;
 	} else {
 		div_debounce_support = false;
-- 
2.34.1