1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/rtc/rtc-at32ap700x.c b/drivers/rtc/rtc-at32ap700x.c
index e725d51e773d..8dd08305aae1 100644
--- a/drivers/rtc/rtc-at32ap700x.c
+++ b/drivers/rtc/rtc-at32ap700x.c
@@ -223,7 +223,7 @@ static int __init at32_rtc_probe(struct platform_device *pdev)
         }
 
         rtc->irq = irq;
-        rtc->regs = ioremap(regs->start, regs->end - regs->start + 1);
+        rtc->regs = ioremap(regs->start, resource_size(regs));
         if (!rtc->regs) {
                 ret = -ENOMEM;
                 dev_dbg(&pdev->dev, "could not map I/O memory\n");