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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>
This commit is contained in:
Anurag Kumar Vulisha 2016-04-12 17:45:44 +05:30 committed by Alexandre Belloni
parent 19105f424b
commit 9092984f1a
1 changed files with 8 additions and 0 deletions
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8
drivers/rtc/rtc-zynqmp.c
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@ -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