staging: comedi: add comedi_write_array_to_buffer()

The "comedi_fc" module contains a few functions useful to Comedi
drivers.  Their functionality is being migrated to the core "comedi"
module and renamed to start with the prefix `comedi_`.  As part of this
migration, move `cfc_write_array_to_buffer()` into the core comedi
module and rename it to `comedi_write_array_to_buffer()`.  Change the
external declaration of `cfc_write_array_to_buffer()` into an inline
function that calls `comedi_write_array_to_buffer()`.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 27 insertions, 0 deletions

diff --git a/drivers/staging/comedi/comedi_buf.c b/drivers/staging/comedi/comedi_buf.c
index df4a9c4bca35..5aa86842fcce 100644
--- a/drivers/staging/comedi/comedi_buf.c
+++ b/drivers/staging/comedi/comedi_buf.c
@@ -509,3 +509,30 @@ void comedi_buf_memcpy_from(struct comedi_subdevice *s, unsigned int offset,
 	}
 }
 EXPORT_SYMBOL_GPL(comedi_buf_memcpy_from);
+
+/* Writes an array of data points to comedi's buffer */
+unsigned int comedi_write_array_to_buffer(struct comedi_subdevice *s,
+					  const void *data,
+					  unsigned int num_bytes)
+{
+	struct comedi_async *async = s->async;
+	unsigned int retval;
+
+	if (num_bytes == 0)
+		return 0;
+
+	retval = comedi_buf_write_alloc(s, num_bytes);
+	if (retval != num_bytes) {
+		dev_warn(s->device->class_dev, "buffer overrun\n");
+		async->events |= COMEDI_CB_OVERFLOW;
+		return 0;
+	}
+
+	comedi_buf_memcpy_to(s, 0, data, num_bytes);
+	comedi_buf_write_free(s, num_bytes);
+	comedi_inc_scan_progress(s, num_bytes);
+	async->events |= COMEDI_CB_BLOCK;
+
+	return num_bytes;
+}
+EXPORT_SYMBOL_GPL(comedi_write_array_to_buffer);