watchdog: rzg2l_wdt: Fix 32bit overflow issue

The value of timer_cycle_us can be 0 due to 32bit overflow.
For eg:- If we assign the counter value "0xfff" for computing
maxval.

This patch fixes this issue by appending ULL to 1024, so that
it is promoted to 64bit.

This patch also fixes the warning message, 'watchdog: Invalid min and
max timeout values, resetting to 0!'.

Fixes: 2cbc5cd0b55fa2 ("watchdog: Add Watchdog Timer driver for RZ/G2L")
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20220225175320.11041-2-biju.das.jz@bp.renesas.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
index 6b426df34fd6fd728639210b2b9a19639012b30a..96f2a018ab6261aa1916a20518a30004eed67d90 100644 (file)
--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -53,7 +53,7 @@ static void rzg2l_wdt_wait_delay(struct rzg2l_wdt_priv *priv)
 
 static u32 rzg2l_wdt_get_cycle_usec(unsigned long cycle, u32 wdttime)
 {
-       u64 timer_cycle_us = 1024 * 1024 * (wdttime + 1) * MICRO;
+       u64 timer_cycle_us = 1024 * 1024ULL * (wdttime + 1) * MICRO;
 
        return div64_ul(timer_cycle_us, cycle);
 }