1 files changed, 38 insertions, 5 deletions

diff --git a/drivers/rtc/rtc-twl.c b/drivers/rtc/rtc-twl.c
index 4c2c6df2a9ef..258abeabf624 100644
--- a/drivers/rtc/rtc-twl.c
+++ b/drivers/rtc/rtc-twl.c
@@ -112,6 +112,7 @@ static const u8 twl6030_rtc_reg_map[] = {
 #define BIT_RTC_CTRL_REG_TEST_MODE_M             0x10
 #define BIT_RTC_CTRL_REG_SET_32_COUNTER_M        0x20
 #define BIT_RTC_CTRL_REG_GET_TIME_M              0x40
+#define BIT_RTC_CTRL_REG_RTC_V_OPT               0x80
 
 /* RTC_STATUS_REG bitfields */
 #define BIT_RTC_STATUS_REG_RUN_M                 0x02
@@ -235,25 +236,57 @@ static int twl_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	unsigned char rtc_data[ALL_TIME_REGS + 1];
 	int ret;
 	u8 save_control;
+	u8 rtc_control;
 
 	ret = twl_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
-	if (ret < 0)
+	if (ret < 0) {
+		dev_err(dev, "%s: reading CTRL_REG, error %d\n", __func__, ret);
 		return ret;
+	}
+	/* for twl6030/32 make sure BIT_RTC_CTRL_REG_GET_TIME_M is clear */
+	if (twl_class_is_6030()) {
+		if (save_control & BIT_RTC_CTRL_REG_GET_TIME_M) {
+			save_control &= ~BIT_RTC_CTRL_REG_GET_TIME_M;
+			ret = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
+			if (ret < 0) {
+				dev_err(dev, "%s clr GET_TIME, error %d\n",
+					__func__, ret);
+				return ret;
+			}
+		}
+	}
 
-	save_control |= BIT_RTC_CTRL_REG_GET_TIME_M;
+	/* Copy RTC counting registers to static registers or latches */
+	rtc_control = save_control | BIT_RTC_CTRL_REG_GET_TIME_M;
 
-	ret = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
-	if (ret < 0)
+	/* for twl6030/32 enable read access to static shadowed registers */
+	if (twl_class_is_6030())
+		rtc_control |= BIT_RTC_CTRL_REG_RTC_V_OPT;
+
+	ret = twl_rtc_write_u8(rtc_control, REG_RTC_CTRL_REG);
+	if (ret < 0) {
+		dev_err(dev, "%s: writing CTRL_REG, error %d\n", __func__, ret);
 		return ret;
+	}
 
 	ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
 			(rtc_reg_map[REG_SECONDS_REG]), ALL_TIME_REGS);
 
 	if (ret < 0) {
-		dev_err(dev, "rtc_read_time error %d\n", ret);
+		dev_err(dev, "%s: reading data, error %d\n", __func__, ret);
 		return ret;
 	}
 
+	/* for twl6030 restore original state of rtc control register */
+	if (twl_class_is_6030()) {
+		ret = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
+		if (ret < 0) {
+			dev_err(dev, "%s: restore CTRL_REG, error %d\n",
+				__func__, ret);
+			return ret;
+		}
+	}
+
 	tm->tm_sec = bcd2bin(rtc_data[0]);
 	tm->tm_min = bcd2bin(rtc_data[1]);
 	tm->tm_hour = bcd2bin(rtc_data[2]);