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 <anuragku@xilinx.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
diff --git a/drivers/rtc/rtc-zynqmp.c b/drivers/rtc/rtc-zynqmp.c
index 8b28762..6adb603 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 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