1 files changed, 12 insertions, 4 deletions

diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
index 8a368756881b..c3cfacca2541 100644
--- a/drivers/iio/adc/ti_am335x_adc.c
+++ b/drivers/iio/adc/ti_am335x_adc.c
@@ -32,6 +32,7 @@
 
 struct tiadc_device {
         struct ti_tscadc_dev *mfd_tscadc;
+        struct mutex fifo1_lock; /* to protect fifo access */
         int channels;
         u8 channel_line[8];
         u8 channel_step[8];
@@ -359,6 +360,7 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
                 int *val, int *val2, long mask)
 {
         struct tiadc_device *adc_dev = iio_priv(indio_dev);
+        int ret = IIO_VAL_INT;
         int i, map_val;
         unsigned int fifo1count, read, stepid;
         bool found = false;
@@ -372,13 +374,14 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
         if (!step_en)
                 return -EINVAL;
 
+        mutex_lock(&adc_dev->fifo1_lock);
         fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
         while (fifo1count--)
                 tiadc_readl(adc_dev, REG_FIFO1);
 
         am335x_tsc_se_set_once(adc_dev->mfd_tscadc, step_en);
 
-        timeout = jiffies + usecs_to_jiffies
+        timeout = jiffies + msecs_to_jiffies
                                 (IDLE_TIMEOUT * adc_dev->channels);
         /* Wait for Fifo threshold interrupt */
         while (1) {
@@ -388,7 +391,8 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
 
                 if (time_after(jiffies, timeout)) {
                         am335x_tsc_se_adc_done(adc_dev->mfd_tscadc);
-                        return -EAGAIN;
+                        ret = -EAGAIN;
+                        goto err_unlock;
                 }
         }
         map_val = adc_dev->channel_step[chan->scan_index];
@@ -414,8 +418,11 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
         am335x_tsc_se_adc_done(adc_dev->mfd_tscadc);
 
         if (found == false)
-                return -EBUSY;
-        return IIO_VAL_INT;
+                ret =  -EBUSY;
+
+err_unlock:
+        mutex_unlock(&adc_dev->fifo1_lock);
+        return ret;
 }
 
 static const struct iio_info tiadc_info = {
@@ -483,6 +490,7 @@ static int tiadc_probe(struct platform_device *pdev)
 
         tiadc_step_config(indio_dev);
         tiadc_writel(adc_dev, REG_FIFO1THR, FIFO1_THRESHOLD);
+        mutex_init(&adc_dev->fifo1_lock);
 
         err = tiadc_channel_init(indio_dev, adc_dev->channels);
         if (err < 0)