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path: root/drivers/rtc/rtc-twl.c
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Diffstat (limited to 'drivers/rtc/rtc-twl.c')
-rw-r--r--drivers/rtc/rtc-twl.c43
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]);