From 9092984f1a8440ea52bf53c2d53bf8f5953a5126 Mon Sep 17 00:00:00 2001 From: Anurag Kumar Vulisha Date: Tue, 12 Apr 2016 17:45:44 +0530 Subject: rtc: zynqmp: Enable RTC switching to battery power when VCC_PSAUX is N/A In order to conserve battery energy, during the PS operation, it is expected that the supply for the battery-powered domain to be switched from the battery (VCC_PSBATT) to (VCC_PSAUX) and automatically be switched back to battery when VCC_PSAUX voltage drops below a limit, doing so prevents the logic within the battery-powered domain from functioning incorrectly. Signed-off-by: Anurag Kumar Vulisha Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-zynqmp.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'drivers/rtc/rtc-zynqmp.c') diff --git a/drivers/rtc/rtc-zynqmp.c b/drivers/rtc/rtc-zynqmp.c index 8b28762f06df..6adb603f29bc 100644 --- a/drivers/rtc/rtc-zynqmp.c +++ b/drivers/rtc/rtc-zynqmp.c @@ -45,6 +45,7 @@ #define RTC_INT_SEC BIT(0) #define RTC_INT_ALRM BIT(1) #define RTC_OSC_EN BIT(24) +#define RTC_BATT_EN BIT(31) #define RTC_CALIB_DEF 0x198233 #define RTC_CALIB_MASK 0x1FFFFF @@ -122,6 +123,13 @@ static int xlnx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) static void xlnx_init_rtc(struct xlnx_rtc_dev *xrtcdev, u32 calibval) { + u32 rtc_ctrl; + + /* Enable RTC switch to battery when VCC_PSAUX is not available */ + rtc_ctrl = readl(xrtcdev->reg_base + RTC_CTRL); + rtc_ctrl |= RTC_BATT_EN; + writel(rtc_ctrl, xrtcdev->reg_base + RTC_CTRL); + /* * Based on crystal freq of 33.330 KHz * set the seconds counter and enable, set fractions counter -- cgit v1.2.3-59-g8ed1b