1 files changed, 20 insertions, 5 deletions

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index d2b465140a6b..cd5bfe39591b 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -166,21 +166,21 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
  * @wait:	Poll table structure pointer for which the driver adds
  *		a wait queue
  *
- * Return: (POLLIN | POLLRDNORM) if data is available for reading
+ * Return: (EPOLLIN | EPOLLRDNORM) if data is available for reading
  *	   or 0 for other cases
  */
-unsigned int iio_buffer_poll(struct file *filp,
+__poll_t iio_buffer_poll(struct file *filp,
 			     struct poll_table_struct *wait)
 {
 	struct iio_dev *indio_dev = filp->private_data;
 	struct iio_buffer *rb = indio_dev->buffer;
 
-	if (!indio_dev->info)
+	if (!indio_dev->info || rb == NULL)
 		return 0;
 
 	poll_wait(filp, &rb->pollq, wait);
 	if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0))
-		return POLLIN | POLLRDNORM;
+		return EPOLLIN | EPOLLRDNORM;
 	return 0;
 }
 
@@ -1198,6 +1198,18 @@ out:
 	return ret ? ret : len;
 }
 
+static ssize_t iio_dma_show_data_available(struct device *dev,
+						struct device_attribute *attr,
+						char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	size_t bytes;
+
+	bytes = iio_buffer_data_available(indio_dev->buffer);
+
+	return sprintf(buf, "%zu\n", bytes);
+}
+
 static DEVICE_ATTR(length, S_IRUGO | S_IWUSR, iio_buffer_read_length,
 		   iio_buffer_write_length);
 static struct device_attribute dev_attr_length_ro = __ATTR(length,
@@ -1208,11 +1220,14 @@ static DEVICE_ATTR(watermark, S_IRUGO | S_IWUSR,
 		   iio_buffer_show_watermark, iio_buffer_store_watermark);
 static struct device_attribute dev_attr_watermark_ro = __ATTR(watermark,
 	S_IRUGO, iio_buffer_show_watermark, NULL);
+static DEVICE_ATTR(data_available, S_IRUGO,
+		iio_dma_show_data_available, NULL);
 
 static struct attribute *iio_buffer_attrs[] = {
 	&dev_attr_length.attr,
 	&dev_attr_enable.attr,
 	&dev_attr_watermark.attr,
+	&dev_attr_data_available.attr,
 };
 
 int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
@@ -1381,7 +1396,7 @@ static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data)
 	 * We can't just test for watermark to decide if we wake the poll queue
 	 * because read may request less samples than the watermark.
 	 */
-	wake_up_interruptible_poll(&buffer->pollq, POLLIN | POLLRDNORM);
+	wake_up_interruptible_poll(&buffer->pollq, EPOLLIN | EPOLLRDNORM);
 	return 0;
 }