diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index dd4bf58..8b119ce 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -53,7 +53,7 @@
 	unsigned long flags;
 
 	spin_lock_irqsave(&tsadc->reg_lock, flags);
-	tsadc->reg_se_cache = val;
+	tsadc->reg_se_cache |= val;
 	if (tsadc->adc_waiting)
 		wake_up(&tsadc->reg_se_wait);
 	else if (!tsadc->adc_in_use)
@@ -96,6 +96,7 @@
 void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val)
 {
 	spin_lock_irq(&tsadc->reg_lock);
+	tsadc->reg_se_cache |= val;
 	am335x_tscadc_need_adc(tsadc);
 
 	tscadc_writel(tsadc, REG_SE, val);