It is suggested to programe CALIB_WRITE register with the calibration value before updating the SET_TIME_WRITE register, doing so will clear the Tick Counter and force the next second to be signaled exactly in 1 second.
This patch updates the same. Signed-off-by: Anurag Kumar Vulisha <[email protected]> --- drivers/rtc/rtc-zynqmp.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/drivers/rtc/rtc-zynqmp.c b/drivers/rtc/rtc-zynqmp.c index 6adb603..f87f971 100644 --- a/drivers/rtc/rtc-zynqmp.c +++ b/drivers/rtc/rtc-zynqmp.c @@ -56,6 +56,7 @@ struct xlnx_rtc_dev { void __iomem *reg_base; int alarm_irq; int sec_irq; + int calibval; }; static int xlnx_rtc_set_time(struct device *dev, struct rtc_time *tm) @@ -68,6 +69,13 @@ static int xlnx_rtc_set_time(struct device *dev, struct rtc_time *tm) if (new_time > RTC_SEC_MAX_VAL) return -EINVAL; + /* + * Writing into calibration register will clear the Tick Counter and + * force the next second to be signaled exactly in 1 second period + */ + xrtcdev->calibval &= RTC_CALIB_MASK; + writel(xrtcdev->calibval, (xrtcdev->reg_base + RTC_CALIB_WR)); + writel(new_time, xrtcdev->reg_base + RTC_SET_TM_WR); return 0; @@ -121,7 +129,7 @@ static int xlnx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) return 0; } -static void xlnx_init_rtc(struct xlnx_rtc_dev *xrtcdev, u32 calibval) +static void xlnx_init_rtc(struct xlnx_rtc_dev *xrtcdev) { u32 rtc_ctrl; @@ -136,8 +144,8 @@ static void xlnx_init_rtc(struct xlnx_rtc_dev *xrtcdev, u32 calibval) * to default value suggested as per design spec * to correct RTC delay in frequency over period of time. */ - calibval &= RTC_CALIB_MASK; - writel(calibval, (xrtcdev->reg_base + RTC_CALIB_WR)); + xrtcdev->calibval &= RTC_CALIB_MASK; + writel(xrtcdev->calibval, (xrtcdev->reg_base + RTC_CALIB_WR)); } static const struct rtc_class_ops xlnx_rtc_ops = { @@ -174,7 +182,6 @@ static int xlnx_rtc_probe(struct platform_device *pdev) struct xlnx_rtc_dev *xrtcdev; struct resource *res; int ret; - unsigned int calibvalue; xrtcdev = devm_kzalloc(&pdev->dev, sizeof(*xrtcdev), GFP_KERNEL); if (!xrtcdev) @@ -215,11 +222,11 @@ static int xlnx_rtc_probe(struct platform_device *pdev) } ret = of_property_read_u32(pdev->dev.of_node, "calibration", - &calibvalue); + &xrtcdev->calibval); if (ret) - calibvalue = RTC_CALIB_DEF; + xrtcdev->calibval = RTC_CALIB_DEF; - xlnx_init_rtc(xrtcdev, calibvalue); + xlnx_init_rtc(xrtcdev); device_init_wakeup(&pdev->dev, 1); -- 2.1.2
