+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/workqueue.h>
+#include <linux/kfifo.h>
+#include <linux/mutex.h>
+
+#include "kfifo_buf.h"
+
+static inline int __iio_allocate_kfifo(struct iio_kfifo *buf,
+ int bytes_per_datum, int length)
+{
+ if ((length == 0) || (bytes_per_datum == 0))
+ return -EINVAL;
+
+ __iio_update_ring_buffer(&buf->ring, bytes_per_datum, length);
+ return kfifo_alloc(&buf->kf, bytes_per_datum*length, GFP_KERNEL);
+}
+
+int iio_request_update_kfifo(struct iio_ring_buffer *r)
+{
+ int ret = 0;
+ struct iio_kfifo *buf = iio_to_kfifo(r);
+
+ mutex_lock(&buf->use_lock);
+ if (!buf->update_needed)
+ goto error_ret;
+ if (buf->use_count) {
+ ret = -EAGAIN;
+ goto error_ret;
+ }
+ kfifo_free(&buf->kf);
+ ret = __iio_allocate_kfifo(buf, buf->ring.bytes_per_datum,
+ buf->ring.length);
+error_ret:
+ mutex_unlock(&buf->use_lock);
+ return ret;
+}
+EXPORT_SYMBOL(iio_request_update_kfifo);
+
+void iio_mark_kfifo_in_use(struct iio_ring_buffer *r)
+{
+ struct iio_kfifo *buf = iio_to_kfifo(r);
+ mutex_lock(&buf->use_lock);
+ buf->use_count++;
+ mutex_unlock(&buf->use_lock);
+}
+EXPORT_SYMBOL(iio_mark_kfifo_in_use);
+
+void iio_unmark_kfifo_in_use(struct iio_ring_buffer *r)
+{
+ struct iio_kfifo *buf = iio_to_kfifo(r);
+ mutex_lock(&buf->use_lock);
+ buf->use_count--;
+ mutex_unlock(&buf->use_lock);
+}
+EXPORT_SYMBOL(iio_unmark_kfifo_in_use);
+
+int iio_get_length_kfifo(struct iio_ring_buffer *r)
+{
+ return r->length;
+}
+EXPORT_SYMBOL(iio_get_length_kfifo);
+
+static inline void __iio_init_kfifo(struct iio_kfifo *kf)
+{
+ mutex_init(&kf->use_lock);
+}
+
+static IIO_RING_ENABLE_ATTR;
+static IIO_RING_BYTES_PER_DATUM_ATTR;
+static IIO_RING_LENGTH_ATTR;
+
+static struct attribute *iio_kfifo_attributes[] = {
+ &dev_attr_length.attr,
+ &dev_attr_bytes_per_datum.attr,
+ &dev_attr_enable.attr,
+ NULL,
+};
+
+static struct attribute_group iio_kfifo_attribute_group = {
+ .attrs = iio_kfifo_attributes,
+};
+
+static const struct attribute_group *iio_kfifo_attribute_groups[] = {
+ &iio_kfifo_attribute_group,
+ NULL
+};
+
+static void iio_kfifo_release(struct device *dev)
+{
+ struct iio_ring_buffer *r = to_iio_ring_buffer(dev);
+ struct iio_kfifo *kf = iio_to_kfifo(r);
+ kfifo_free(&kf->kf);
+ kfree(kf);
+}
+
+static struct device_type iio_kfifo_type = {
+ .release = iio_kfifo_release,
+ .groups = iio_kfifo_attribute_groups,
+};
+
+struct iio_ring_buffer *iio_kfifo_allocate(struct iio_dev *indio_dev)
+{
+ struct iio_kfifo *kf;
+
+ kf = kzalloc(sizeof *kf, GFP_KERNEL);
+ if (!kf)
+ return NULL;
+ iio_ring_buffer_init(&kf->ring, indio_dev);
+ __iio_init_kfifo(kf);
+ kf->ring.dev.type = &iio_kfifo_type;
+ device_initialize(&kf->ring.dev);
+ kf->ring.dev.parent = &indio_dev->dev;
+ kf->ring.dev.bus = &iio_bus_type;
+ dev_set_drvdata(&kf->ring.dev, (void *)&(kf->ring));
+
+ return &kf->ring;
+}
+EXPORT_SYMBOL(iio_kfifo_allocate);
+
+int iio_get_bytes_per_datum_kfifo(struct iio_ring_buffer *r)
+{
+ return r->bytes_per_datum;
+}
+EXPORT_SYMBOL(iio_get_bytes_per_datum_kfifo);
+
+int iio_set_bytes_per_datum_kfifo(struct iio_ring_buffer *r, size_t bpd)
+{
+ if (r->bytes_per_datum != bpd) {
+ r->bytes_per_datum = bpd;
+ if (r->access.mark_param_change)
+ r->access.mark_param_change(r);
+ }
+ return 0;
+}
+EXPORT_SYMBOL(iio_set_bytes_per_datum_kfifo);
+
+int iio_mark_update_needed_kfifo(struct iio_ring_buffer *r)
+{
+ struct iio_kfifo *kf = iio_to_kfifo(r);
+ kf->update_needed = true;
+ return 0;
+}
+EXPORT_SYMBOL(iio_mark_update_needed_kfifo);
+
+int iio_set_length_kfifo(struct iio_ring_buffer *r, int length)
+{
+ if (r->length != length) {
+ r->length = length;
+ if (r->access.mark_param_change)
+ r->access.mark_param_change(r);
+ }
+ return 0;
+}
+EXPORT_SYMBOL(iio_set_length_kfifo);
+
+void iio_kfifo_free(struct iio_ring_buffer *r)
+{
+ if (r)
+ iio_put_ring_buffer(r);
+}
+EXPORT_SYMBOL(iio_kfifo_free);
+
+int iio_store_to_kfifo(struct iio_ring_buffer *r, u8 *data, s64 timestamp)
+{
+ int ret;
+ struct iio_kfifo *kf = iio_to_kfifo(r);
+ u8 *datal = kmalloc(r->bytes_per_datum, GFP_KERNEL);
+ memcpy(datal, data, r->bytes_per_datum - sizeof(timestamp));
+ memcpy(datal + r->bytes_per_datum - sizeof(timestamp),
+ ×tamp, sizeof(timestamp));
+ ret = kfifo_in(&kf->kf, data, r->bytes_per_datum);
+ if (ret != r->bytes_per_datum) {
+ kfree(datal);
+ return -EBUSY;
+ }
+ kfree(datal);
+ return 0;
+}
+EXPORT_SYMBOL(iio_store_to_kfifo);
+
+int iio_rip_kfifo(struct iio_ring_buffer *r,
+ size_t count, char __user *buf, int *deadoffset)
+{
+ int ret, copied;
+ struct iio_kfifo *kf = iio_to_kfifo(r);
+
+ *deadoffset = 0;
+ ret = kfifo_to_user(&kf->kf, buf, r->bytes_per_datum*count, &copied);
+
+ return copied;
+}
+EXPORT_SYMBOL(iio_rip_kfifo);
+MODULE_LICENSE("GPL");