staging:iio: Add polling of events on the ring access chrdev.

Staging one of combining the ring chrdevs.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/iio/industrialio-ring.c b/drivers/staging/iio/industrialio-ring.c
index 5d7cd0e7cc571213e4a6e518d85ae6734f78be72..5c3f4660c49f94779eae8dd1dd430efe790e7683 100644 (file)
--- a/drivers/staging/iio/industrialio-ring.c
+++ b/drivers/staging/iio/industrialio-ring.c
@@ -18,6 +18,7 @@
 #include <linux/fs.h>
 #include <linux/cdev.h>
 #include <linux/slab.h>
+#include <linux/poll.h>
 
 #include "iio.h"
 #include "ring_generic.h"
@@ -90,10 +91,27 @@ static ssize_t iio_ring_read_first_n_outer(struct file *filp, char __user *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;
+       int ret = 0;
+
+       poll_wait(filp, &rb->pollq, wait);
+       if (rb->stufftoread)
+               return POLLIN | POLLRDNORM;
+       /* need a way of knowing if there may be enough data... */
+       return ret;
+}
+
 static const struct file_operations iio_ring_fileops = {
        .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,
 };
@@ -211,6 +229,7 @@ void iio_ring_buffer_init(struct iio_ring_buffer *ring,
        ring->indio_dev = dev_info;
        ring->ev_int.private = ring;
        ring->access_handler.private = ring;
+       init_waitqueue_head(&ring->pollq);
 }
 EXPORT_SYMBOL(iio_ring_buffer_init);
 
@@ -392,7 +411,7 @@ int iio_ring_buffer_register_ex(struct iio_ring_buffer *ring, int id,
                                                      ring->owner);
 
        if (ret)
-               goto error_free_ring_buffer_event_chrdev;
+               goto error_ret;
 
        if (ring->scan_el_attrs) {
                ret = sysfs_create_group(&ring->dev.kobj,
@@ -400,13 +419,13 @@ int iio_ring_buffer_register_ex(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_access_chrdev;
                }
        } else if (channels) {
                ret = sysfs_create_group(&ring->dev.kobj,
                                         &iio_scan_el_dummy_group);
                if (ret)
-                       goto error_free_ring_buffer_event_chrdev;
+                       goto error_free_ring_buffer_access_chrdev;
        }
 
 
@@ -424,8 +443,8 @@ int iio_ring_buffer_register_ex(struct iio_ring_buffer *ring, int id,
        return 0;
 error_cleanup_dynamic:
        __iio_ring_attr_cleanup(ring);
-error_free_ring_buffer_event_chrdev:
-       __iio_free_ring_buffer_event_chrdev(ring);
+error_free_ring_buffer_access_chrdev:
+       __iio_free_ring_buffer_access_chrdev(ring);
 error_remove_device:
        device_del(&ring->dev);
 error_ret:

diff --git a/drivers/staging/iio/ring_generic.h b/drivers/staging/iio/ring_generic.h
index d51c21c42297e4c497c1f6398364863c3692c24b..0640a8ae8b5105db722b1730a34e3f9a58fbe14e 100644 (file)
--- a/drivers/staging/iio/ring_generic.h
+++ b/drivers/staging/iio/ring_generic.h
@@ -139,6 +139,9 @@ struct iio_ring_buffer {
 
        struct list_head scan_el_dev_attr_list;
        struct list_head scan_el_en_attr_list;
+
+       wait_queue_head_t pollq;
+       bool stufftoread;
 };
 
 /**

diff --cc drivers/staging/iio/ring_sw.c
Simple merge