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>
This commit is contained in:
Jonathan Cameron 2011-05-18 14:40:55 +01:00 committed by Greg Kroah-Hartman
parent 939606d5cc
commit a7348347ba
3 changed files with 35 additions and 5 deletions

View File

@ -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:

View File

@ -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;
};
/**

View File

@ -12,6 +12,7 @@
#include <linux/module.h>
#include <linux/device.h>
#include <linux/workqueue.h>
#include <linux/sched.h>
#include <linux/poll.h>
#include "ring_sw.h"
#include "trigger.h"
@ -136,6 +137,8 @@ static int iio_store_to_sw_ring(struct iio_sw_ring_buffer *ring,
ret = __iio_push_event(&ring->buf.ev_int,
code,
timestamp);
ring->buf.stufftoread = true;
wake_up_interruptible(&ring->buf.pollq);
}
return ret;
}
@ -261,6 +264,10 @@ int iio_read_first_n_sw_rb(struct iio_ring_buffer *r,
ret = -EFAULT;
goto error_free_data_cpy;
}
if (bytes_to_rip >= ring->buf.length*ring->buf.bytes_per_datum/2)
ring->buf.stufftoread = 0;
error_free_data_cpy:
kfree(data);
error_ret:
@ -310,6 +317,7 @@ int iio_request_update_sw_rb(struct iio_ring_buffer *r)
int ret = 0;
struct iio_sw_ring_buffer *ring = iio_to_sw_ring(r);
r->stufftoread = false;
spin_lock(&ring->use_lock);
if (!ring->update_needed)
goto error_ret;