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authorLars-Peter Clausen2013-11-25 14:56:00 +0000
committerJonathan Cameron2013-12-03 20:22:28 +0000
commit647cc7b9be861e01723a3183f5d06729a1613a97 (patch)
treeee1dfdc4fc2f51b8af65bf5e5de09c9be1969bb7 /drivers
parent112b0b79b2e7a552e8afe19fdddbacef734649f8 (diff)
iio: Add data_available callback for buffers
This patch adds a new data_available() callback to the iio_buffer_access_funcs struct. The callback is used to indicate whether data is available in the buffer for reading. It is meant to replace the stufftoread flag from the iio_buffer struct. The reasoning for this is that the buffer implementation usually can determine whether data is available rather easily based on its state, on the other hand it can be rather tricky to update the stufftoread flag in a race free way. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/iio/industrialio-buffer.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 7f9152c3c4d3..4dcc3a0f9930 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -37,6 +37,14 @@ static bool iio_buffer_is_active(struct iio_buffer *buf)
return !list_empty(&buf->buffer_list);
}
+static bool iio_buffer_data_available(struct iio_buffer *buf)
+{
+ if (buf->access->data_available)
+ return buf->access->data_available(buf);
+
+ return buf->stufftoread;
+}
+
/**
* iio_buffer_read_first_n_outer() - chrdev read for buffer access
*
@@ -70,7 +78,7 @@ unsigned int iio_buffer_poll(struct file *filp,
return -ENODEV;
poll_wait(filp, &rb->pollq, wait);
- if (rb->stufftoread)
+ if (iio_buffer_data_available(rb))
return POLLIN | POLLRDNORM;
/* need a way of knowing if there may be enough data... */
return 0;