[PATCH] rtc: brcmstb-waketimer: fix settime function

[Arnd Bergmann]

gcc warns about an unused variable in the new driver:

drivers/rtc/rtc-brcmstb-waketimer.c: In function 'brcmstb_waketmr_settime':
drivers/rtc/rtc-brcmstb-waketimer.c:142:6: error: unused variable 'ret' 
[-Werror=unused-variable]

The same function also doesn't handle overflow correctly, this makes
it return -EINVAL when passed a time that doesn't fit within the
range of the register.

Fixes: 9f4ad359c801 ("rtc: brcmstb-waketimer: Add Broadcom STB wake-timer")
Signed-off-by: Arnd Bergmann <a...@arndb.de>
---
 drivers/rtc/rtc-brcmstb-waketimer.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/rtc/rtc-brcmstb-waketimer.c 
b/drivers/rtc/rtc-brcmstb-waketimer.c
index 5dea6d0627d8..796ac792a381 100644
--- a/drivers/rtc/rtc-brcmstb-waketimer.c
+++ b/drivers/rtc/rtc-brcmstb-waketimer.c
@@ -138,10 +138,12 @@ static int brcmstb_waketmr_settime(struct device *dev,
                                   struct rtc_time *tm)
 {
        struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
-       unsigned long sec;
-       int ret;
+       time64_t sec;
+
+       sec = rtc_tm_to_time64(tm);
 
-       rtc_tm_to_time(tm, &sec);
+       if (sec > U32_MAX || sec < 0)
+               return -EINVAL;
 
        writel_relaxed(sec, timer->base + BRCMSTB_WKTMR_COUNTER);
 
@@ -152,14 +154,14 @@ static int brcmstb_waketmr_getalarm(struct device *dev,
                                    struct rtc_wkalrm *alarm)
 {
        struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
-       unsigned long sec;
+       time64_t sec;
        u32 reg;
 
        sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_ALARM);
        if (sec != 0) {
                /* Alarm is enabled */
                alarm->enabled = 1;
-               rtc_time_to_tm(sec, &alarm->time);
+               rtc_time64_to_tm(sec, &alarm->time);
        }
 
        reg = readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
@@ -172,13 +174,16 @@ static int brcmstb_waketmr_setalarm(struct device *dev,
                                     struct rtc_wkalrm *alarm)
 {
        struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
-       unsigned long sec;
+       time64_t sec;
 
        if (alarm->enabled)
-               rtc_tm_to_time(&alarm->time, &sec);
+               sec = rtc_tm_to_time64(&alarm->time);
        else
                sec = 0;
 
+       if (sec > U32_MAX || sec < 0)
+               return -EINVAL;
+
        brcmstb_waketmr_set_alarm(timer, sec);
 
        return 0;
-- 
2.9.0