staging:iio:buffer add a cache of the timestamp scan index.

Basically avoids looking it up lots of times.

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

diff --git a/drivers/staging/iio/buffer.h b/drivers/staging/iio/buffer.h
index 9de581e..4b8f619 100644 (file)
--- a/drivers/staging/iio/buffer.h
+++ b/drivers/staging/iio/buffer.h
@@ -106,6 +106,7 @@ struct iio_buffer {
        int                                     scan_count;
        long                                    *scan_mask;
        bool                                    scan_timestamp;
+       unsigned                                scan_index_timestamp;
        const struct iio_buffer_access_funcs    *access;
        const struct iio_buffer_setup_ops               *setup_ops;
        struct list_head                        scan_el_dev_attr_list;

diff --git a/drivers/staging/iio/industrialio-buffer.c b/drivers/staging/iio/industrialio-buffer.c
index 8c55980..b2cf3e3 100644 (file)
--- a/drivers/staging/iio/industrialio-buffer.c
+++ b/drivers/staging/iio/industrialio-buffer.c
@@ -313,6 +313,9 @@ int iio_buffer_register(struct iio_dev *indio_dev,
                        if (ret < 0)
                                goto error_cleanup_dynamic;
                        attrcount += ret;
+                       if (channels[i].type == IIO_TIMESTAMP)
+                               buffer->scan_index_timestamp =
+                                       channels[i].scan_index;
                }
                if (indio_dev->masklength && buffer->scan_mask == NULL) {
                        buffer->scan_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),