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path: root/drivers/iio/adc/ti_am335x_adc.c
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Diffstat (limited to 'drivers/iio/adc/ti_am335x_adc.c')
-rw-r--r--drivers/iio/adc/ti_am335x_adc.c16
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)