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author | Jonathan Cameron | 2011-05-18 15:40:55 +0200 |
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committer | Greg Kroah-Hartman | 2011-05-20 01:06:12 +0200 |
commit | a7348347ba8a4a961a88434d37e45a8bd98a47b0 (patch) | |
tree | 7fa8e32b722db5eb49df9e93f9eac3cd3001d34d /drivers/staging/iio/industrialio-ring.c | |
parent | staging:iio: remove ability to escalate events. (diff) | |
download | kernel-qcow2-linux-a7348347ba8a4a961a88434d37e45a8bd98a47b0.tar.gz kernel-qcow2-linux-a7348347ba8a4a961a88434d37e45a8bd98a47b0.tar.xz kernel-qcow2-linux-a7348347ba8a4a961a88434d37e45a8bd98a47b0.zip |
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>
Diffstat (limited to 'drivers/staging/iio/industrialio-ring.c')
-rw-r--r-- | drivers/staging/iio/industrialio-ring.c | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/drivers/staging/iio/industrialio-ring.c b/drivers/staging/iio/industrialio-ring.c index 5d7cd0e7cc57..5c3f4660c49f 100644 --- 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: |