Commit c0e9e6ba authored by Jonathan Cameron's avatar Jonathan Cameron Committed by Greg Kroah-Hartman
Browse files

staging:iio:ring_sw don't provide read last function. 



No longer needed as we don't have drivers providing sysfs access
to buffered data.

Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
Acked-by: default avatarLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 3ca34cc4

drivers/staging/iio/ring_sw.c

+0 −33
Original line number Diff line number Diff line
@@ -23,7 +23,6 @@ 
 * @data:		the ring buffer memory

 * @read_p:		read pointer (oldest available)

 * @write_p:		write pointer

 * @last_written_p:	read pointer (newest available)

 * @half_p:		half buffer length behind write_p (event generation)

 * @use_count:		reference count to prevent resizing when in use

 * @update_needed:	flag to indicated change in size requested
@@ -37,7 +36,6 @@ struct iio_sw_ring_buffer { 
	unsigned char		*data;

	unsigned char		*read_p;

	unsigned char		*write_p;

	unsigned char		*last_written_p;

	/* used to act as a point at which to signal an event */

	unsigned char		*half_p;

	int			use_count;
@@ -56,7 +54,6 @@ static inline int __iio_allocate_sw_ring_buffer(struct iio_sw_ring_buffer *ring, 
	ring->data = kmalloc(length*ring->buf.bytes_per_datum, GFP_ATOMIC);

	ring->read_p = NULL;

	ring->write_p = NULL;

	ring->last_written_p = NULL;

	ring->half_p = NULL;

	return ring->data ? 0 : -ENOMEM;

}
@@ -115,7 +112,6 @@ static int iio_store_to_sw_ring(struct iio_sw_ring_buffer *ring, 
	 * Always valid as either points to latest or second latest value.

	 * Before this runs it is null and read attempts fail with -EAGAIN.

	 */

	ring->last_written_p = ring->write_p;

	barrier();

	/* temp_ptr used to ensure we never have an invalid pointer

	 * it may be slightly lagging, but never invalid
@@ -305,34 +301,6 @@ static int iio_store_to_sw_rb(struct iio_buffer *r, 
	return iio_store_to_sw_ring(ring, data, timestamp);

}



static int iio_read_last_from_sw_ring(struct iio_sw_ring_buffer *ring,

				      unsigned char *data)

{

	unsigned char *last_written_p_copy;



	iio_mark_sw_rb_in_use(&ring->buf);

again:

	barrier();

	last_written_p_copy = ring->last_written_p;

	barrier(); /*unnessecary? */

	/* Check there is anything here */

	if (last_written_p_copy == NULL)

		return -EAGAIN;

	memcpy(data, last_written_p_copy, ring->buf.bytes_per_datum);



	if (unlikely(ring->last_written_p != last_written_p_copy))

		goto again;



	iio_unmark_sw_rb_in_use(&ring->buf);

	return 0;

}



static int iio_read_last_from_sw_rb(struct iio_buffer *r,

			     unsigned char *data)

{

	return iio_read_last_from_sw_ring(iio_to_sw_ring(r), data);

}



static int iio_request_update_sw_rb(struct iio_buffer *r)

{

	int ret = 0;
@@ -435,7 +403,6 @@ const struct iio_buffer_access_funcs ring_sw_access_funcs = { 
	.mark_in_use = &iio_mark_sw_rb_in_use,

	.unmark_in_use = &iio_unmark_sw_rb_in_use,

	.store_to = &iio_store_to_sw_rb,

	.read_last = &iio_read_last_from_sw_rb,

	.read_first_n = &iio_read_first_n_sw_rb,

	.mark_param_change = &iio_mark_update_needed_sw_rb,

	.request_update = &iio_request_update_sw_rb,