2 files changed, 6 insertions, 8 deletions

diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index 467c80e1c4ae..e4e4b22eebc9 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -68,12 +68,6 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
         DEFINE_WAIT(wait);
         u32 reg;
 
-        /*
-         * disable TSC steps so it does not run while the ADC is using it. If
-         * write 0 while it is running (it just started or was already running)
-         * then it completes all steps that were enabled and stops then.
-         */
-        tscadc_writel(tsadc, REG_SE, 0);
         reg = tscadc_readl(tsadc, REG_ADCFSM);
         if (reg & SEQ_STATUS) {
                 tsadc->adc_waiting = true;
@@ -86,8 +80,12 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
                 spin_lock_irq(&tsadc->reg_lock);
                 finish_wait(&tsadc->reg_se_wait, &wait);
 
+                /*
+                 * Sequencer should either be idle or
+                 * busy applying the charge step.
+                 */
                 reg = tscadc_readl(tsadc, REG_ADCFSM);
-                WARN_ON(reg & SEQ_STATUS);
+                WARN_ON((reg & SEQ_STATUS) && !(reg & CHARGE_STEP));
                 tsadc->adc_waiting = false;
         }
         tsadc->adc_in_use = true;
@@ -96,7 +94,6 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
 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);
diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
index 3f4e994ace2b..1fd50dcfe47c 100644
--- a/include/linux/mfd/ti_am335x_tscadc.h
+++ b/include/linux/mfd/ti_am335x_tscadc.h
@@ -128,6 +128,7 @@
 
 /* Sequencer Status */
 #define SEQ_STATUS BIT(5)
+#define CHARGE_STEP             0x11
 
 #define ADC_CLK                 3000000
 #define TOTAL_STEPS             16