1 files changed, 139 insertions, 0 deletions
diff --git a/drivers/iio/buffer/industrialio-triggered-buffer.c b/drivers/iio/buffer/industrialio-triggered-buffer.c
new file mode 100644
index 000000000..2b7873e8a
--- /dev/null
+++ b/drivers/iio/buffer/industrialio-triggered-buffer.c
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0-only
+ /*
+ * Copyright (c) 2012 Analog Devices, Inc.
+ *  Author: Lars-Peter Clausen <lars@metafoo.de>
+ */
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/buffer_impl.h>
+#include <linux/iio/kfifo_buf.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+/**
+ * iio_triggered_buffer_setup_ext() - Setup triggered buffer and pollfunc
+ * @indio_dev:		IIO device structure
+ * @h:			Function which will be used as pollfunc top half
+ * @thread:		Function which will be used as pollfunc bottom half
+ * @direction:		Direction of the data stream (in/out).
+ * @setup_ops:		Buffer setup functions to use for this device.
+ *			If NULL the default setup functions for triggered
+ *			buffers will be used.
+ * @buffer_attrs:	Extra sysfs buffer attributes for this IIO buffer
+ *
+ * This function combines some common tasks which will normally be performed
+ * when setting up a triggered buffer. It will allocate the buffer and the
+ * pollfunc.
+ *
+ * Before calling this function the indio_dev structure should already be
+ * completely initialized, but not yet registered. In practice this means that
+ * this function should be called right before iio_device_register().
+ *
+ * To free the resources allocated by this function call
+ * iio_triggered_buffer_cleanup().
+ */
+int iio_triggered_buffer_setup_ext(struct iio_dev *indio_dev,
+	irqreturn_t (*h)(int irq, void *p),
+	irqreturn_t (*thread)(int irq, void *p),
+	enum iio_buffer_direction direction,
+	const struct iio_buffer_setup_ops *setup_ops,
+	const struct attribute **buffer_attrs)
+{
+	struct iio_buffer *buffer;
+	int ret;
+
+	/*
+	 * iio_triggered_buffer_cleanup() assumes that the buffer allocated here
+	 * is assigned to indio_dev->buffer but this is only the case if this
+	 * function is the first caller to iio_device_attach_buffer(). If
+	 * indio_dev->buffer is already set then we can't proceed otherwise the
+	 * cleanup function will try to free a buffer that was not allocated here.
+	 */
+	if (indio_dev->buffer)
+		return -EADDRINUSE;
+
+	buffer = iio_kfifo_allocate();
+	if (!buffer) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+
+	indio_dev->pollfunc = iio_alloc_pollfunc(h,
+						 thread,
+						 IRQF_ONESHOT,
+						 indio_dev,
+						 "%s_consumer%d",
+						 indio_dev->name,
+						 iio_device_id(indio_dev));
+	if (indio_dev->pollfunc == NULL) {
+		ret = -ENOMEM;
+		goto error_kfifo_free;
+	}
+
+	/* Ring buffer functions - here trigger setup related */
+	indio_dev->setup_ops = setup_ops;
+
+	/* Flag that polled ring buffering is possible */
+	indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
+
+	buffer->direction = direction;
+	buffer->attrs = buffer_attrs;
+
+	ret = iio_device_attach_buffer(indio_dev, buffer);
+	if (ret < 0)
+		goto error_dealloc_pollfunc;
+
+	return 0;
+
+error_dealloc_pollfunc:
+	iio_dealloc_pollfunc(indio_dev->pollfunc);
+error_kfifo_free:
+	iio_kfifo_free(buffer);
+error_ret:
+	return ret;
+}
+EXPORT_SYMBOL(iio_triggered_buffer_setup_ext);
+
+/**
+ * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup_ext()
+ * @indio_dev: IIO device structure
+ */
+void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
+{
+	iio_dealloc_pollfunc(indio_dev->pollfunc);
+	iio_kfifo_free(indio_dev->buffer);
+}
+EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
+
+static void devm_iio_triggered_buffer_clean(void *indio_dev)
+{
+	iio_triggered_buffer_cleanup(indio_dev);
+}
+
+int devm_iio_triggered_buffer_setup_ext(struct device *dev,
+					struct iio_dev *indio_dev,
+					irqreturn_t (*h)(int irq, void *p),
+					irqreturn_t (*thread)(int irq, void *p),
+					enum iio_buffer_direction direction,
+					const struct iio_buffer_setup_ops *ops,
+					const struct attribute **buffer_attrs)
+{
+	int ret;
+
+	ret = iio_triggered_buffer_setup_ext(indio_dev, h, thread, direction,
+					     ops, buffer_attrs);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(dev, devm_iio_triggered_buffer_clean,
+					indio_dev);
+}
+EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_setup_ext);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
+MODULE_LICENSE("GPL");