]> Pileus Git - ~andy/linux/blobdiff - drivers/staging/iio/industrialio-ring.c
Merge branch 'iommu-for-tony' of git://github.com/ohadbc/omap-iommu into devel-fixes
[~andy/linux] / drivers / staging / iio / industrialio-ring.c
index bd4373ae066bd5030ee21961d9b86bd3e20b86d8..843eb82a69ba34e7601d79cc1a4dba0a4ca335eb 100644 (file)
 #include <linux/fs.h>
 #include <linux/cdev.h>
 #include <linux/slab.h>
+#include <linux/poll.h>
 
 #include "iio.h"
 #include "ring_generic.h"
 
-int iio_push_ring_event(struct iio_ring_buffer *ring_buf,
-                      int event_code,
-                      s64 timestamp)
-{
-       return __iio_push_event(&ring_buf->ev_int,
-                              event_code,
-                              timestamp,
-                              &ring_buf->shared_ev_pointer);
-}
-EXPORT_SYMBOL(iio_push_ring_event);
-
-int iio_push_or_escallate_ring_event(struct iio_ring_buffer *ring_buf,
-                                   int event_code,
-                                   s64 timestamp)
-{
-       if (ring_buf->shared_ev_pointer.ev_p)
-               __iio_change_event(ring_buf->shared_ev_pointer.ev_p,
-                                  event_code,
-                                  timestamp);
-       else
-               return iio_push_ring_event(ring_buf,
-                                         event_code,
-                                         timestamp);
-       return 0;
-}
-EXPORT_SYMBOL(iio_push_or_escallate_ring_event);
-
 /**
  * iio_ring_open() - chrdev file open for ring buffer access
  *
@@ -62,8 +36,8 @@ static int iio_ring_open(struct inode *inode, struct file *filp)
        struct iio_ring_buffer *rb = hand->private;
 
        filp->private_data = hand->private;
-       if (rb->access.mark_in_use)
-               rb->access.mark_in_use(rb);
+       if (rb->access->mark_in_use)
+               rb->access->mark_in_use(rb);
 
        return 0;
 }
@@ -81,184 +55,316 @@ static int iio_ring_release(struct inode *inode, struct file *filp)
        struct iio_ring_buffer *rb = hand->private;
 
        clear_bit(IIO_BUSY_BIT_POS, &rb->access_handler.flags);
-       if (rb->access.unmark_in_use)
-               rb->access.unmark_in_use(rb);
+       if (rb->access->unmark_in_use)
+               rb->access->unmark_in_use(rb);
 
        return 0;
 }
 
 /**
- * iio_ring_rip_outer() - chrdev read for ring buffer access
+ * iio_ring_read_first_n_outer() - chrdev read for ring buffer access
  *
  * This function relies on all ring buffer implementations having an
  * iio_ring _bufer as their first element.
  **/
-static ssize_t iio_ring_rip_outer(struct file *filp, char __user *buf,
-                                 size_t count, loff_t *f_ps)
+static ssize_t iio_ring_read_first_n_outer(struct file *filp, char __user *buf,
+                                 size_t n, loff_t *f_ps)
 {
        struct iio_ring_buffer *rb = filp->private_data;
-       int ret, dead_offset;
 
-       /* rip lots must exist. */
-       if (!rb->access.rip_lots)
+       if (!rb->access->read_first_n)
                return -EINVAL;
-       ret = rb->access.rip_lots(rb, count, buf, &dead_offset);
+       return rb->access->read_first_n(rb, n, buf);
+}
 
-       return ret;
+/**
+ * iio_ring_poll() - poll the ring to find out if it has data
+ */
+static unsigned int iio_ring_poll(struct file *filp,
+                                 struct poll_table_struct *wait)
+{
+       struct iio_ring_buffer *rb = filp->private_data;
+
+       poll_wait(filp, &rb->pollq, wait);
+       if (rb->stufftoread)
+               return POLLIN | POLLRDNORM;
+       /* need a way of knowing if there may be enough data... */
+       return 0;
 }
 
 static const struct file_operations iio_ring_fileops = {
-       .read = iio_ring_rip_outer,
+       .read = iio_ring_read_first_n_outer,
        .release = iio_ring_release,
        .open = iio_ring_open,
+       .poll = iio_ring_poll,
        .owner = THIS_MODULE,
        .llseek = noop_llseek,
 };
 
-/**
- * __iio_request_ring_buffer_event_chrdev() - allocate ring event chrdev
- * @buf:       ring buffer whose event chrdev we are allocating
- * @id:                id of this ring buffer (typically 0)
- * @owner:     the module who owns the ring buffer (for ref counting)
- * @dev:       device with which the chrdev is associated
- **/
-static inline int
-__iio_request_ring_buffer_event_chrdev(struct iio_ring_buffer *buf,
-                                      int id,
-                                      struct module *owner,
-                                      struct device *dev)
-{
-       int ret;
-
-       snprintf(buf->ev_int._name, sizeof(buf->ev_int._name),
-                "%s:event%d",
-                dev_name(&buf->dev),
-                id);
-       ret = iio_setup_ev_int(&(buf->ev_int),
-                              buf->ev_int._name,
-                              owner,
-                              dev);
-       if (ret)
-               goto error_ret;
-       return 0;
-
-error_ret:
-       return ret;
-}
-
-static inline void
-__iio_free_ring_buffer_event_chrdev(struct iio_ring_buffer *buf)
-{
-       iio_free_ev_int(&(buf->ev_int));
-}
-
-static void iio_ring_access_release(struct device *dev)
+void iio_ring_access_release(struct device *dev)
 {
        struct iio_ring_buffer *buf
-               = access_dev_to_iio_ring_buffer(dev);
+               = container_of(dev, struct iio_ring_buffer, dev);
        cdev_del(&buf->access_handler.chrdev);
        iio_device_free_chrdev_minor(MINOR(dev->devt));
 }
-
-static struct device_type iio_ring_access_type = {
-       .release = iio_ring_access_release,
-};
+EXPORT_SYMBOL(iio_ring_access_release);
 
 static inline int
-__iio_request_ring_buffer_access_chrdev(struct iio_ring_buffer *buf,
-                                       int id,
-                                       struct module *owner)
+__iio_request_ring_buffer_chrdev(struct iio_ring_buffer *buf,
+                                struct module *owner,
+                                int id)
 {
-       int ret, minor;
+       int ret;
 
        buf->access_handler.flags = 0;
+       buf->dev.bus = &iio_bus_type;
+       device_initialize(&buf->dev);
 
-       buf->access_dev.parent = &buf->dev;
-       buf->access_dev.bus = &iio_bus_type;
-       buf->access_dev.type = &iio_ring_access_type;
-       device_initialize(&buf->access_dev);
-
-       minor = iio_device_get_chrdev_minor();
-       if (minor < 0) {
-               ret = minor;
+       ret = iio_device_get_chrdev_minor();
+       if (ret < 0)
                goto error_device_put;
-       }
-       buf->access_dev.devt = MKDEV(MAJOR(iio_devt), minor);
 
-
-       buf->access_id = id;
-
-       dev_set_name(&buf->access_dev, "%s:access%d",
-                    dev_name(&buf->dev),
-                    buf->access_id);
-       ret = device_add(&buf->access_dev);
+       buf->dev.devt = MKDEV(MAJOR(iio_devt), ret);
+       dev_set_name(&buf->dev, "%s:buffer%d",
+                    dev_name(buf->dev.parent),
+                    id);
+       ret = device_add(&buf->dev);
        if (ret < 0) {
-               printk(KERN_ERR "failed to add the ring access dev\n");
+               printk(KERN_ERR "failed to add the ring dev\n");
                goto error_device_put;
        }
-
        cdev_init(&buf->access_handler.chrdev, &iio_ring_fileops);
        buf->access_handler.chrdev.owner = owner;
-
-       ret = cdev_add(&buf->access_handler.chrdev, buf->access_dev.devt, 1);
+       ret = cdev_add(&buf->access_handler.chrdev, buf->dev.devt, 1);
        if (ret) {
-               printk(KERN_ERR "failed to allocate ring access chrdev\n");
+               printk(KERN_ERR "failed to allocate ring chrdev\n");
                goto error_device_unregister;
        }
        return 0;
 
 error_device_unregister:
-       device_unregister(&buf->access_dev);
+       device_unregister(&buf->dev);
 error_device_put:
-       put_device(&buf->access_dev);
+       put_device(&buf->dev);
 
        return ret;
 }
 
-static void __iio_free_ring_buffer_access_chrdev(struct iio_ring_buffer *buf)
+static void __iio_free_ring_buffer_chrdev(struct iio_ring_buffer *buf)
 {
-       device_unregister(&buf->access_dev);
+       device_unregister(&buf->dev);
 }
 
 void iio_ring_buffer_init(struct iio_ring_buffer *ring,
                          struct iio_dev *dev_info)
 {
-       if (ring->access.mark_param_change)
-               ring->access.mark_param_change(ring);
        ring->indio_dev = dev_info;
-       ring->ev_int.private = ring;
        ring->access_handler.private = ring;
-       ring->shared_ev_pointer.ev_p = NULL;
-       spin_lock_init(&ring->shared_ev_pointer.lock);
+       init_waitqueue_head(&ring->pollq);
 }
 EXPORT_SYMBOL(iio_ring_buffer_init);
 
-int iio_ring_buffer_register(struct iio_ring_buffer *ring, int id)
+static ssize_t iio_show_scan_index(struct device *dev,
+                                  struct device_attribute *attr,
+                                  char *buf)
+{
+       return sprintf(buf, "%u\n", to_iio_dev_attr(attr)->c->scan_index);
+}
+
+static ssize_t iio_show_fixed_type(struct device *dev,
+                                  struct device_attribute *attr,
+                                  char *buf)
+{
+       struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+       return sprintf(buf, "%c%d/%d>>%u\n",
+                      this_attr->c->scan_type.sign,
+                      this_attr->c->scan_type.realbits,
+                      this_attr->c->scan_type.storagebits,
+                      this_attr->c->scan_type.shift);
+}
+
+static ssize_t iio_scan_el_show(struct device *dev,
+                               struct device_attribute *attr,
+                               char *buf)
 {
        int ret;
+       struct iio_ring_buffer *ring = dev_get_drvdata(dev);
+
+       ret = iio_scan_mask_query(ring, to_iio_dev_attr(attr)->address);
+       if (ret < 0)
+               return ret;
+       return sprintf(buf, "%d\n", ret);
+}
 
-       ring->id = id;
+static int iio_scan_mask_clear(struct iio_ring_buffer *ring, int bit)
+{
+       if (bit > IIO_MAX_SCAN_LENGTH)
+               return -EINVAL;
+       ring->scan_mask &= ~(1 << bit);
+       ring->scan_count--;
+       return 0;
+}
+
+static ssize_t iio_scan_el_store(struct device *dev,
+                                struct device_attribute *attr,
+                                const char *buf,
+                                size_t len)
+{
+       int ret = 0;
+       bool state;
+       struct iio_ring_buffer *ring = dev_get_drvdata(dev);
+       struct iio_dev *indio_dev = ring->indio_dev;
+       struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+       state = !(buf[0] == '0');
+       mutex_lock(&indio_dev->mlock);
+       if (indio_dev->currentmode == INDIO_RING_TRIGGERED) {
+               ret = -EBUSY;
+               goto error_ret;
+       }
+       ret = iio_scan_mask_query(ring, this_attr->address);
+       if (ret < 0)
+               goto error_ret;
+       if (!state && ret) {
+               ret = iio_scan_mask_clear(ring, this_attr->address);
+               if (ret)
+                       goto error_ret;
+       } else if (state && !ret) {
+               ret = iio_scan_mask_set(ring, this_attr->address);
+               if (ret)
+                       goto error_ret;
+       }
+
+error_ret:
+       mutex_unlock(&indio_dev->mlock);
+
+       return ret ? ret : len;
+
+}
+
+static ssize_t iio_scan_el_ts_show(struct device *dev,
+                                  struct device_attribute *attr,
+                                  char *buf)
+{
+       struct iio_ring_buffer *ring = dev_get_drvdata(dev);
+       return sprintf(buf, "%d\n", ring->scan_timestamp);
+}
+
+static ssize_t iio_scan_el_ts_store(struct device *dev,
+                                   struct device_attribute *attr,
+                                   const char *buf,
+                                   size_t len)
+{
+       int ret = 0;
+       struct iio_ring_buffer *ring = dev_get_drvdata(dev);
+       struct iio_dev *indio_dev = ring->indio_dev;
+       bool state;
+       state = !(buf[0] == '0');
+       mutex_lock(&indio_dev->mlock);
+       if (indio_dev->currentmode == INDIO_RING_TRIGGERED) {
+               ret = -EBUSY;
+               goto error_ret;
+       }
+       ring->scan_timestamp = state;
+error_ret:
+       mutex_unlock(&indio_dev->mlock);
 
-       dev_set_name(&ring->dev, "%s:buffer%d",
-                    dev_name(ring->dev.parent),
-                    ring->id);
-       ret = device_add(&ring->dev);
+       return ret ? ret : len;
+}
+
+static int iio_ring_add_channel_sysfs(struct iio_ring_buffer *ring,
+                                     const struct iio_chan_spec *chan)
+{
+       int ret;
+
+       ret = __iio_add_chan_devattr("index", "scan_elements",
+                                    chan,
+                                    &iio_show_scan_index,
+                                    NULL,
+                                    0,
+                                    0,
+                                    &ring->dev,
+                                    &ring->scan_el_dev_attr_list);
        if (ret)
                goto error_ret;
 
-       ret = __iio_request_ring_buffer_event_chrdev(ring,
-                                                    0,
-                                                    ring->owner,
-                                                    &ring->dev);
+       ret = __iio_add_chan_devattr("type", "scan_elements",
+                                    chan,
+                                    &iio_show_fixed_type,
+                                    NULL,
+                                    0,
+                                    0,
+                                    &ring->dev,
+                                    &ring->scan_el_dev_attr_list);
        if (ret)
-               goto error_remove_device;
+               goto error_ret;
+
+       if (chan->type != IIO_TIMESTAMP)
+               ret = __iio_add_chan_devattr("en", "scan_elements",
+                                            chan,
+                                            &iio_scan_el_show,
+                                            &iio_scan_el_store,
+                                            chan->scan_index,
+                                            0,
+                                            &ring->dev,
+                                            &ring->scan_el_dev_attr_list);
+       else
+               ret = __iio_add_chan_devattr("en", "scan_elements",
+                                            chan,
+                                            &iio_scan_el_ts_show,
+                                            &iio_scan_el_ts_store,
+                                            chan->scan_index,
+                                            0,
+                                            &ring->dev,
+                                            &ring->scan_el_dev_attr_list);
+error_ret:
+       return ret;
+}
+
+static void iio_ring_remove_and_free_scan_dev_attr(struct iio_ring_buffer *ring,
+                                                  struct iio_dev_attr *p)
+{
+       sysfs_remove_file_from_group(&ring->dev.kobj,
+                                    &p->dev_attr.attr, "scan_elements");
+       kfree(p->dev_attr.attr.name);
+       kfree(p);
+}
+
+static struct attribute *iio_scan_el_dummy_attrs[] = {
+       NULL
+};
+
+static struct attribute_group iio_scan_el_dummy_group = {
+       .name = "scan_elements",
+       .attrs = iio_scan_el_dummy_attrs
+};
+
+static void __iio_ring_attr_cleanup(struct iio_ring_buffer *ring)
+{
+       struct iio_dev_attr *p, *n;
+       int anydynamic = !list_empty(&ring->scan_el_dev_attr_list);
+       list_for_each_entry_safe(p, n,
+                                &ring->scan_el_dev_attr_list, l)
+               iio_ring_remove_and_free_scan_dev_attr(ring, p);
+
+       if (ring->scan_el_attrs)
+               sysfs_remove_group(&ring->dev.kobj,
+                                  ring->scan_el_attrs);
+       else if (anydynamic)
+               sysfs_remove_group(&ring->dev.kobj,
+                                  &iio_scan_el_dummy_group);
+}
 
-       ret = __iio_request_ring_buffer_access_chrdev(ring,
-                                                     0,
-                                                     ring->owner);
+int iio_ring_buffer_register_ex(struct iio_ring_buffer *ring, int id,
+                               const struct iio_chan_spec *channels,
+                               int num_channels)
+{
+       int ret, i;
 
+       ret = __iio_request_ring_buffer_chrdev(ring, ring->owner, id);
        if (ret)
-               goto error_free_ring_buffer_event_chrdev;
+               goto error_ret;
 
        if (ring->scan_el_attrs) {
                ret = sysfs_create_group(&ring->dev.kobj,
@@ -266,29 +372,39 @@ int iio_ring_buffer_register(struct iio_ring_buffer *ring, int id)
                if (ret) {
                        dev_err(&ring->dev,
                                "Failed to add sysfs scan elements\n");
-                       goto error_free_ring_buffer_event_chrdev;
+                       goto error_free_ring_buffer_chrdev;
                }
+       } else if (channels) {
+               ret = sysfs_create_group(&ring->dev.kobj,
+                                        &iio_scan_el_dummy_group);
+               if (ret)
+                       goto error_free_ring_buffer_chrdev;
        }
 
-       return ret;
-error_free_ring_buffer_event_chrdev:
-       __iio_free_ring_buffer_event_chrdev(ring);
-error_remove_device:
-       device_del(&ring->dev);
+       INIT_LIST_HEAD(&ring->scan_el_dev_attr_list);
+       if (channels) {
+               /* new magic */
+               for (i = 0; i < num_channels; i++) {
+                       ret = iio_ring_add_channel_sysfs(ring, &channels[i]);
+                       if (ret < 0)
+                               goto error_cleanup_dynamic;
+               }
+       }
+
+       return 0;
+error_cleanup_dynamic:
+       __iio_ring_attr_cleanup(ring);
+error_free_ring_buffer_chrdev:
+       __iio_free_ring_buffer_chrdev(ring);
 error_ret:
        return ret;
 }
-EXPORT_SYMBOL(iio_ring_buffer_register);
+EXPORT_SYMBOL(iio_ring_buffer_register_ex);
 
 void iio_ring_buffer_unregister(struct iio_ring_buffer *ring)
 {
-       if (ring->scan_el_attrs)
-               sysfs_remove_group(&ring->dev.kobj,
-                                  ring->scan_el_attrs);
-
-       __iio_free_ring_buffer_access_chrdev(ring);
-       __iio_free_ring_buffer_event_chrdev(ring);
-       device_del(&ring->dev);
+       __iio_ring_attr_cleanup(ring);
+       __iio_free_ring_buffer_chrdev(ring);
 }
 EXPORT_SYMBOL(iio_ring_buffer_unregister);
 
@@ -296,14 +412,13 @@ ssize_t iio_read_ring_length(struct device *dev,
                             struct device_attribute *attr,
                             char *buf)
 {
-       int len = 0;
        struct iio_ring_buffer *ring = dev_get_drvdata(dev);
 
-       if (ring->access.get_length)
-               len = sprintf(buf, "%d\n",
-                             ring->access.get_length(ring));
+       if (ring->access->get_length)
+               return sprintf(buf, "%d\n",
+                              ring->access->get_length(ring));
 
-       return len;
+       return 0;
 }
 EXPORT_SYMBOL(iio_read_ring_length);
 
@@ -315,18 +430,19 @@ ssize_t iio_write_ring_length(struct device *dev,
        int ret;
        ulong val;
        struct iio_ring_buffer *ring = dev_get_drvdata(dev);
+
        ret = strict_strtoul(buf, 10, &val);
        if (ret)
                return ret;
 
-       if (ring->access.get_length)
-               if (val == ring->access.get_length(ring))
+       if (ring->access->get_length)
+               if (val == ring->access->get_length(ring))
                        return len;
 
-       if (ring->access.set_length) {
-               ring->access.set_length(ring, val);
-               if (ring->access.mark_param_change)
-                       ring->access.mark_param_change(ring);
+       if (ring->access->set_length) {
+               ring->access->set_length(ring, val);
+               if (ring->access->mark_param_change)
+                       ring->access->mark_param_change(ring);
        }
 
        return len;
@@ -337,14 +453,13 @@ ssize_t iio_read_ring_bytes_per_datum(struct device *dev,
                          struct device_attribute *attr,
                          char *buf)
 {
-       int len = 0;
        struct iio_ring_buffer *ring = dev_get_drvdata(dev);
 
-       if (ring->access.get_bytes_per_datum)
-               len = sprintf(buf, "%d\n",
-                             ring->access.get_bytes_per_datum(ring));
+       if (ring->access->get_bytes_per_datum)
+               return sprintf(buf, "%d\n",
+                              ring->access->get_bytes_per_datum(ring));
 
-       return len;
+       return 0;
 }
 EXPORT_SYMBOL(iio_read_ring_bytes_per_datum);
 
@@ -368,8 +483,8 @@ ssize_t iio_store_ring_enable(struct device *dev,
                goto done;
        }
        if (requested_state) {
-               if (ring->preenable) {
-                       ret = ring->preenable(dev_info);
+               if (ring->setup_ops->preenable) {
+                       ret = ring->setup_ops->preenable(dev_info);
                        if (ret) {
                                printk(KERN_ERR
                                       "Buffer not started:"
@@ -377,8 +492,8 @@ ssize_t iio_store_ring_enable(struct device *dev,
                                goto error_ret;
                        }
                }
-               if (ring->access.request_update) {
-                       ret = ring->access.request_update(ring);
+               if (ring->access->request_update) {
+                       ret = ring->access->request_update(ring);
                        if (ret) {
                                printk(KERN_INFO
                                       "Buffer not started:"
@@ -386,16 +501,16 @@ ssize_t iio_store_ring_enable(struct device *dev,
                                goto error_ret;
                        }
                }
-               if (ring->access.mark_in_use)
-                       ring->access.mark_in_use(ring);
+               if (ring->access->mark_in_use)
+                       ring->access->mark_in_use(ring);
                /* Definitely possible for devices to support both of these.*/
                if (dev_info->modes & INDIO_RING_TRIGGERED) {
                        if (!dev_info->trig) {
                                printk(KERN_INFO
                                       "Buffer not started: no trigger\n");
                                ret = -EINVAL;
-                               if (ring->access.unmark_in_use)
-                                       ring->access.unmark_in_use(ring);
+                               if (ring->access->unmark_in_use)
+                                       ring->access->unmark_in_use(ring);
                                goto error_ret;
                        }
                        dev_info->currentmode = INDIO_RING_TRIGGERED;
@@ -406,32 +521,31 @@ ssize_t iio_store_ring_enable(struct device *dev,
                        goto error_ret;
                }
 
-               if (ring->postenable) {
-
-                       ret = ring->postenable(dev_info);
+               if (ring->setup_ops->postenable) {
+                       ret = ring->setup_ops->postenable(dev_info);
                        if (ret) {
                                printk(KERN_INFO
                                       "Buffer not started:"
                                       "postenable failed\n");
-                               if (ring->access.unmark_in_use)
-                                       ring->access.unmark_in_use(ring);
+                               if (ring->access->unmark_in_use)
+                                       ring->access->unmark_in_use(ring);
                                dev_info->currentmode = previous_mode;
-                               if (ring->postdisable)
-                                       ring->postdisable(dev_info);
+                               if (ring->setup_ops->postdisable)
+                                       ring->setup_ops->postdisable(dev_info);
                                goto error_ret;
                        }
                }
        } else {
-               if (ring->predisable) {
-                       ret = ring->predisable(dev_info);
+               if (ring->setup_ops->predisable) {
+                       ret = ring->setup_ops->predisable(dev_info);
                        if (ret)
                                goto error_ret;
                }
-               if (ring->access.unmark_in_use)
-                       ring->access.unmark_in_use(ring);
+               if (ring->access->unmark_in_use)
+                       ring->access->unmark_in_use(ring);
                dev_info->currentmode = INDIO_DIRECT_MODE;
-               if (ring->postdisable) {
-                       ret = ring->postdisable(dev_info);
+               if (ring->setup_ops->postdisable) {
+                       ret = ring->setup_ops->postdisable(dev_info);
                        if (ret)
                                goto error_ret;
                }
@@ -445,6 +559,7 @@ error_ret:
        return ret;
 }
 EXPORT_SYMBOL(iio_store_ring_enable);
+
 ssize_t iio_show_ring_enable(struct device *dev,
                                    struct device_attribute *attr,
                                    char *buf)
@@ -455,89 +570,27 @@ ssize_t iio_show_ring_enable(struct device *dev,
 }
 EXPORT_SYMBOL(iio_show_ring_enable);
 
-ssize_t iio_scan_el_show(struct device *dev,
-                        struct device_attribute *attr,
-                        char *buf)
-{
-       int ret;
-       struct iio_ring_buffer *ring = dev_get_drvdata(dev);
-       struct iio_scan_el *this_el = to_iio_scan_el(attr);
-
-       ret = iio_scan_mask_query(ring, this_el->number);
-       if (ret < 0)
-               return ret;
-       return sprintf(buf, "%d\n", ret);
-}
-EXPORT_SYMBOL(iio_scan_el_show);
-
-ssize_t iio_scan_el_store(struct device *dev,
-                         struct device_attribute *attr,
-                         const char *buf,
-                         size_t len)
-{
-       int ret = 0;
-       bool state;
-       struct iio_ring_buffer *ring = dev_get_drvdata(dev);
-       struct iio_dev *indio_dev = ring->indio_dev;
-       struct iio_scan_el *this_el = to_iio_scan_el(attr);
-
-       state = !(buf[0] == '0');
-       mutex_lock(&indio_dev->mlock);
-       if (indio_dev->currentmode == INDIO_RING_TRIGGERED) {
-               ret = -EBUSY;
-               goto error_ret;
-       }
-       ret = iio_scan_mask_query(ring, this_el->number);
-       if (ret < 0)
-               goto error_ret;
-       if (!state && ret) {
-               ret = iio_scan_mask_clear(ring, this_el->number);
-               if (ret)
-                       goto error_ret;
-       } else if (state && !ret) {
-               ret = iio_scan_mask_set(ring, this_el->number);
-               if (ret)
-                       goto error_ret;
-       }
-       if (this_el->set_state)
-               ret = this_el->set_state(this_el, indio_dev, state);
-error_ret:
-       mutex_unlock(&indio_dev->mlock);
-
-       return ret ? ret : len;
-
-}
-EXPORT_SYMBOL(iio_scan_el_store);
-
-ssize_t iio_scan_el_ts_show(struct device *dev,
-                           struct device_attribute *attr,
-                           char *buf)
-{
-       struct iio_ring_buffer *ring = dev_get_drvdata(dev);
-       return sprintf(buf, "%d\n", ring->scan_timestamp);
-}
-EXPORT_SYMBOL(iio_scan_el_ts_show);
-
-ssize_t iio_scan_el_ts_store(struct device *dev,
-                            struct device_attribute *attr,
-                            const char *buf,
-                            size_t len)
+int iio_sw_ring_preenable(struct iio_dev *indio_dev)
 {
-       int ret = 0;
-       struct iio_ring_buffer *ring = dev_get_drvdata(dev);
-       struct iio_dev *indio_dev = ring->indio_dev;
-       bool state;
-       state = !(buf[0] == '0');
-       mutex_lock(&indio_dev->mlock);
-       if (indio_dev->currentmode == INDIO_RING_TRIGGERED) {
-               ret = -EBUSY;
-               goto error_ret;
-       }
-       ring->scan_timestamp = state;
-error_ret:
-       mutex_unlock(&indio_dev->mlock);
+       struct iio_ring_buffer *ring = indio_dev->ring;
+       size_t size;
+       dev_dbg(&indio_dev->dev, "%s\n", __func__);
+       /* Check if there are any scan elements enabled, if not fail*/
+       if (!(ring->scan_count || ring->scan_timestamp))
+               return -EINVAL;
+       if (ring->scan_timestamp)
+               if (ring->scan_count)
+                       /* Timestamp (aligned to s64) and data */
+                       size = (((ring->scan_count * ring->bpe)
+                                       + sizeof(s64) - 1)
+                               & ~(sizeof(s64) - 1))
+                               + sizeof(s64);
+               else /* Timestamp only  */
+                       size = sizeof(s64);
+       else /* Data only */
+               size = ring->scan_count * ring->bpe;
+       ring->access->set_bytes_per_datum(ring, size);
 
-       return ret ? ret : len;
+       return 0;
 }
-EXPORT_SYMBOL(iio_scan_el_ts_store);
-
+EXPORT_SYMBOL(iio_sw_ring_preenable);