diff options
Diffstat (limited to 'drivers/iio/adc/ti_am335x_adc.c')
| -rw-r--r-- | drivers/iio/adc/ti_am335x_adc.c | 16 |
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) |