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-rw-r--r--drivers/iio/buffer/industrialio-triggered-buffer.c139
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 0000000000..c06515987e
--- /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 iio_dev_attr **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 iio_dev_attr **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");