1 files changed, 79 insertions, 0 deletions
diff --git a/drivers/iio/common/st_sensors/st_sensors_buffer.c b/drivers/iio/common/st_sensors/st_sensors_buffer.c
new file mode 100644
index 000000000..e2f108ca9
--- /dev/null
+++ b/drivers/iio/common/st_sensors/st_sensors_buffer.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * STMicroelectronics sensors buffer library driver
+ *
+ * Copyright 2012-2013 STMicroelectronics Inc.
+ *
+ * Denis Ciocca <denis.ciocca@st.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+#include <linux/interrupt.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/irqreturn.h>
+#include <linux/regmap.h>
+
+#include <linux/iio/common/st_sensors.h>
+
+
+static int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf)
+{
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+	unsigned int num_data_channels = sdata->num_data_channels;
+	int i;
+
+	for_each_set_bit(i, indio_dev->active_scan_mask, num_data_channels) {
+		const struct iio_chan_spec *channel = &indio_dev->channels[i];
+		unsigned int bytes_to_read =
+			DIV_ROUND_UP(channel->scan_type.realbits +
+				     channel->scan_type.shift, 8);
+		unsigned int storage_bytes =
+			channel->scan_type.storagebits >> 3;
+
+		buf = PTR_ALIGN(buf, storage_bytes);
+		if (regmap_bulk_read(sdata->regmap, channel->address,
+				     buf, bytes_to_read) < 0)
+			return -EIO;
+
+		/* Advance the buffer pointer */
+		buf += storage_bytes;
+	}
+
+	return 0;
+}
+
+irqreturn_t st_sensors_trigger_handler(int irq, void *p)
+{
+	int len;
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct st_sensor_data *sdata = iio_priv(indio_dev);
+	s64 timestamp;
+
+	/*
+	 * If we do timestamping here, do it before reading the values, because
+	 * once we've read the values, new interrupts can occur (when using
+	 * the hardware trigger) and the hw_timestamp may get updated.
+	 * By storing it in a local variable first, we are safe.
+	 */
+	if (iio_trigger_using_own(indio_dev))
+		timestamp = sdata->hw_timestamp;
+	else
+		timestamp = iio_get_time_ns(indio_dev);
+
+	len = st_sensors_get_buffer_element(indio_dev, sdata->buffer_data);
+	if (len < 0)
+		goto st_sensors_get_buffer_element_error;
+
+	iio_push_to_buffers_with_timestamp(indio_dev, sdata->buffer_data,
+					   timestamp);
+
+st_sensors_get_buffer_element_error:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+EXPORT_SYMBOL_NS(st_sensors_trigger_handler, IIO_ST_SENSORS);