diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index 0b6f0abf3370..6bf79072179f 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -1295,3 +1295,72 @@ Description:
 		allows the application to block on poll with a timeout and read
 		the available samples after the timeout expires and thus have a
 		maximum delay guarantee.
+
+What:		/sys/bus/iio/devices/iio:deviceX/buffer/hwfifo_enabled
+KernelVersion: 4.2
+Contact:	linux-iio@vger.kernel.org
+Description:
+		A read-only boolean value that indicates if the hardware fifo is
+		currently enabled or disabled. If the device does not have a
+		hardware fifo this entry is not present.
+		The hardware fifo is enabled when the buffer is enabled if the
+		current hardware fifo watermark level is set and other current
+		device settings allows it (e.g. if a trigger is set that samples
+		data differently that the hardware fifo does then hardware fifo
+		will not enabled).
+		If the hardware fifo is enabled and the level of the hardware
+		fifo reaches the hardware fifo watermark level the device will
+		flush its hardware fifo to the device buffer. Doing a non
+		blocking read on the device when no samples are present in the
+		device buffer will also force a flush.
+		When the hardware fifo is enabled there is no need to use a
+		trigger to use buffer mode since the watermark settings
+		guarantees that the hardware fifo is flushed to the device
+		buffer.
+
+What:		/sys/bus/iio/devices/iio:deviceX/buffer/hwfifo_watermark
+KernelVersion: 4.2
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Read-only entry that contains a single integer specifying the
+		current watermark level for the hardware fifo. If the device
+		does not have a hardware fifo this entry is not present.
+		The watermark level for the hardware fifo is set by the driver
+		based on the value set by the user in buffer/watermark but
+		taking into account hardware limitations (e.g. most hardware
+		buffers are limited to 32-64 samples, some hardware buffers
+		watermarks are fixed or have minimum levels).  A value of 0
+		means that the hardware watermark is unset.
+
+What:		/sys/bus/iio/devices/iio:deviceX/buffer/hwfifo_watermark_min
+KernelVersion: 4.2
+Contact:       linux-iio@vger.kernel.org
+Description:
+		A single positive integer specifying the minimum watermark level
+		for the hardware fifo of this device. If the device does not
+		have a hardware fifo this entry is not present.
+		If the user sets buffer/watermark to a value less than this one,
+		then the hardware watermark will remain unset.
+
+What:	       /sys/bus/iio/devices/iio:deviceX/buffer/hwfifo_watermark_max
+KernelVersion: 4.2
+Contact:       linux-iio@vger.kernel.org
+Description:
+		A single positive integer specifying the maximum watermark level
+		for the hardware fifo of this device. If the device does not
+		have a hardware fifo this entry is not present.
+		If the user sets buffer/watermark to a value greater than this
+		one, then the hardware watermark will be capped at this value.
+
+What:	       /sys/bus/iio/devices/iio:deviceX/buffer/hwfifo_watermark_available
+KernelVersion: 4.2
+Contact:       linux-iio@vger.kernel.org
+Description:
+		A list of positive integers specifying the available watermark
+		levels for the hardware fifo. This entry is optional and if it
+		is not present it means that all the values between
+		hwfifo_watermark_min and hwfifo_watermark_max are supported.
+		If the user sets buffer/watermark to a value greater than
+		hwfifo_watermak_min but not equal to any of the values in this
+		list, the driver will chose an appropriate value for the
+		hardware fifo watermark level.
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index a24b2e005eb3..df919f44d513 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -42,18 +42,47 @@ static size_t iio_buffer_data_available(struct iio_buffer *buf)
 	return buf->access->data_available(buf);
 }
 
-static bool iio_buffer_ready(struct iio_dev *indio_dev, struct iio_buffer *buf,
-			     size_t to_wait)
+static int iio_buffer_flush_hwfifo(struct iio_dev *indio_dev,
+				   struct iio_buffer *buf, size_t required)
 {
+	if (!indio_dev->info->hwfifo_flush_to_buffer)
+		return -ENODEV;
+
+	return indio_dev->info->hwfifo_flush_to_buffer(indio_dev, required);
+}
+
+static bool iio_buffer_ready(struct iio_dev *indio_dev, struct iio_buffer *buf,
+			     size_t to_wait, int to_flush)
+{
+	size_t avail;
+	int flushed = 0;
+
 	/* wakeup if the device was unregistered */
 	if (!indio_dev->info)
 		return true;
 
 	/* drain the buffer if it was disabled */
-	if (!iio_buffer_is_active(buf))
+	if (!iio_buffer_is_active(buf)) {
 		to_wait = min_t(size_t, to_wait, 1);
+		to_flush = 0;
+	}
 
-	if (iio_buffer_data_available(buf) >= to_wait)
+	avail = iio_buffer_data_available(buf);
+
+	if (avail >= to_wait) {
+		/* force a flush for non-blocking reads */
+		if (!to_wait && !avail && to_flush)
+			iio_buffer_flush_hwfifo(indio_dev, buf, to_flush);
+		return true;
+	}
+
+	if (to_flush)
+		flushed = iio_buffer_flush_hwfifo(indio_dev, buf,
+						  to_wait - avail);
+	if (flushed <= 0)
+		return false;
+
+	if (avail + flushed >= to_wait)
 		return true;
 
 	return false;
@@ -72,6 +101,7 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
 	struct iio_buffer *rb = indio_dev->buffer;
 	size_t datum_size;
 	size_t to_wait = 0;
+	size_t to_read;
 	int ret;
 
 	if (!indio_dev->info)
@@ -89,12 +119,14 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
 	if (!datum_size)
 		return 0;
 
+	to_read = min_t(size_t, n / datum_size, rb->watermark);
+
 	if (!(filp->f_flags & O_NONBLOCK))
-		to_wait = min_t(size_t, n / datum_size, rb->watermark);
+		to_wait = to_read;
 
 	do {
 		ret = wait_event_interruptible(rb->pollq,
-				      iio_buffer_ready(indio_dev, rb, to_wait));
+			iio_buffer_ready(indio_dev, rb, to_wait, to_read));
 		if (ret)
 			return ret;
 
@@ -122,7 +154,7 @@ unsigned int iio_buffer_poll(struct file *filp,
 		return -ENODEV;
 
 	poll_wait(filp, &rb->pollq, wait);
-	if (iio_buffer_ready(indio_dev, rb, rb->watermark))
+	if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0))
 		return POLLIN | POLLRDNORM;
 	return 0;
 }
@@ -661,19 +693,16 @@ static int __iio_update_buffers(struct iio_dev *indio_dev,
 		}
 	}
 	/* Definitely possible for devices to support both of these. */
-	if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) {
-		if (!indio_dev->trig) {
-			printk(KERN_INFO "Buffer not started: no trigger\n");
-			ret = -EINVAL;
-			/* Can only occur on first buffer */
-			goto error_run_postdisable;
-		}
+	if ((indio_dev->modes & INDIO_BUFFER_TRIGGERED) && indio_dev->trig) {
 		indio_dev->currentmode = INDIO_BUFFER_TRIGGERED;
 	} else if (indio_dev->modes & INDIO_BUFFER_HARDWARE) {
 		indio_dev->currentmode = INDIO_BUFFER_HARDWARE;
 	} else if (indio_dev->modes & INDIO_BUFFER_SOFTWARE) {
 		indio_dev->currentmode = INDIO_BUFFER_SOFTWARE;
 	} else { /* Should never be reached */
+		/* Can only occur on first buffer */
+		if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
+			pr_info("Buffer not started: no trigger\n");
 		ret = -EINVAL;
 		goto error_run_postdisable;
 	}
@@ -825,6 +854,9 @@ static ssize_t iio_buffer_store_watermark(struct device *dev,
 	}
 
 	buffer->watermark = val;
+
+	if (indio_dev->info->hwfifo_set_watermark)
+		indio_dev->info->hwfifo_set_watermark(indio_dev, val);
 out:
 	mutex_unlock(&indio_dev->mlock);
 
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index 80d855061064..d86b753e9b30 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -338,6 +338,16 @@ struct iio_dev;
  *			provide a custom of_xlate function that reads the
  *			*args* and returns the appropriate index in registered
  *			IIO channels array.
+ * @hwfifo_set_watermark: function pointer to set the current hardware
+ *			fifo watermark level; see hwfifo_* entries in
+ *			Documentation/ABI/testing/sysfs-bus-iio for details on
+ *			how the hardware fifo operates
+ * @hwfifo_flush_to_buffer: function pointer to flush the samples stored
+ *			in the hardware fifo to the device buffer. The driver
+ *			should not flush more than count samples. The function
+ *			must return the number of samples flushed, 0 if no
+ *			samples were flushed or a negative integer if no samples
+ *			were flushed and there was an error.
  **/
 struct iio_info {
 	struct module			*driver_module;
@@ -399,6 +409,9 @@ struct iio_info {
 				  unsigned *readval);
 	int (*of_xlate)(struct iio_dev *indio_dev,
 			const struct of_phandle_args *iiospec);
+	int (*hwfifo_set_watermark)(struct iio_dev *indio_dev, unsigned val);
+	int (*hwfifo_flush_to_buffer)(struct iio_dev *indio_dev,
+				      unsigned count);
 };
 
 /**