rtc: mt6397: fix alarm register overwrite

Alarm registers high byte was reserved for other functions.
This add mask in alarm registers operation functions.
This also fix error condition in interrupt handler.

Fixes: fc2979118f3f ("rtc: mediatek: Add MT6397 RTC driver")
Signed-off-by: Ran Bi <ran.bi@mediatek.com>
Signed-off-by: Hsin-Hsiung Wang <hsin-hsiung.wang@mediatek.com>
Link: https://lore.kernel.org/r/1576057435-3561-6-git-send-email-hsin-hsiung.wang@mediatek.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/drivers/rtc/rtc-mt6397.c b/drivers/rtc/rtc-mt6397.c
index 5249fc99fd5fb7b2eadbdf9a14c3ef2c7b94c96f..9135e21017523959d257484f272b493232bb7b28 100644 (file)
--- a/drivers/rtc/rtc-mt6397.c
+++ b/drivers/rtc/rtc-mt6397.c
@@ -47,7 +47,7 @@ static irqreturn_t mtk_rtc_irq_handler_thread(int irq, void *data)
                irqen = irqsta & ~RTC_IRQ_EN_AL;
                mutex_lock(&rtc->lock);
                if (regmap_write(rtc->regmap, rtc->addr_base + RTC_IRQ_EN,
-                                irqen) < 0)
+                                irqen) == 0)
                        mtk_rtc_write_trigger(rtc);
                mutex_unlock(&rtc->lock);
 
@@ -169,12 +169,12 @@ static int mtk_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
        alm->pending = !!(pdn2 & RTC_PDN2_PWRON_ALARM);
        mutex_unlock(&rtc->lock);
 
-       tm->tm_sec = data[RTC_OFFSET_SEC];
-       tm->tm_min = data[RTC_OFFSET_MIN];
-       tm->tm_hour = data[RTC_OFFSET_HOUR];
-       tm->tm_mday = data[RTC_OFFSET_DOM];
-       tm->tm_mon = data[RTC_OFFSET_MTH];
-       tm->tm_year = data[RTC_OFFSET_YEAR];
+       tm->tm_sec = data[RTC_OFFSET_SEC] & RTC_AL_SEC_MASK;
+       tm->tm_min = data[RTC_OFFSET_MIN] & RTC_AL_MIN_MASK;
+       tm->tm_hour = data[RTC_OFFSET_HOUR] & RTC_AL_HOU_MASK;
+       tm->tm_mday = data[RTC_OFFSET_DOM] & RTC_AL_DOM_MASK;
+       tm->tm_mon = data[RTC_OFFSET_MTH] & RTC_AL_MTH_MASK;
+       tm->tm_year = data[RTC_OFFSET_YEAR] & RTC_AL_YEA_MASK;
 
        tm->tm_year += RTC_MIN_YEAR_OFFSET;
        tm->tm_mon--;
@@ -195,14 +195,25 @@ static int mtk_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
        tm->tm_year -= RTC_MIN_YEAR_OFFSET;
        tm->tm_mon++;
 
-       data[RTC_OFFSET_SEC] = tm->tm_sec;
-       data[RTC_OFFSET_MIN] = tm->tm_min;
-       data[RTC_OFFSET_HOUR] = tm->tm_hour;
-       data[RTC_OFFSET_DOM] = tm->tm_mday;
-       data[RTC_OFFSET_MTH] = tm->tm_mon;
-       data[RTC_OFFSET_YEAR] = tm->tm_year;
-
        mutex_lock(&rtc->lock);
+       ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_AL_SEC,
+                              data, RTC_OFFSET_COUNT);
+       if (ret < 0)
+               goto exit;
+
+       data[RTC_OFFSET_SEC] = ((data[RTC_OFFSET_SEC] & ~(RTC_AL_SEC_MASK)) |
+                               (tm->tm_sec & RTC_AL_SEC_MASK));
+       data[RTC_OFFSET_MIN] = ((data[RTC_OFFSET_MIN] & ~(RTC_AL_MIN_MASK)) |
+                               (tm->tm_min & RTC_AL_MIN_MASK));
+       data[RTC_OFFSET_HOUR] = ((data[RTC_OFFSET_HOUR] & ~(RTC_AL_HOU_MASK)) |
+                               (tm->tm_hour & RTC_AL_HOU_MASK));
+       data[RTC_OFFSET_DOM] = ((data[RTC_OFFSET_DOM] & ~(RTC_AL_DOM_MASK)) |
+                               (tm->tm_mday & RTC_AL_DOM_MASK));
+       data[RTC_OFFSET_MTH] = ((data[RTC_OFFSET_MTH] & ~(RTC_AL_MTH_MASK)) |
+                               (tm->tm_mon & RTC_AL_MTH_MASK));
+       data[RTC_OFFSET_YEAR] = ((data[RTC_OFFSET_YEAR] & ~(RTC_AL_YEA_MASK)) |
+                               (tm->tm_year & RTC_AL_YEA_MASK));
+
        if (alm->enabled) {
                ret = regmap_bulk_write(rtc->regmap,
                                        rtc->addr_base + RTC_AL_SEC,

diff --git a/include/linux/mfd/mt6397/rtc.h b/include/linux/mfd/mt6397/rtc.h
index f84b9163c0ee60f47a4afa1a3f03930881e73859..7dfb63b8137355ef6cf83ebce12cc54ff7d91aa8 100644 (file)
--- a/include/linux/mfd/mt6397/rtc.h
+++ b/include/linux/mfd/mt6397/rtc.h
@@ -46,6 +46,14 @@
 
 #define RTC_AL_SEC             0x0018
 
+#define RTC_AL_SEC_MASK        0x003f
+#define RTC_AL_MIN_MASK        0x003f
+#define RTC_AL_HOU_MASK        0x001f
+#define RTC_AL_DOM_MASK        0x001f
+#define RTC_AL_DOW_MASK        0x0007
+#define RTC_AL_MTH_MASK        0x000f
+#define RTC_AL_YEA_MASK        0x007f
+
 #define RTC_PDN2               0x002e
 #define RTC_PDN2_PWRON_ALARM   BIT(4)