staging: comedi: comedi_fc: export cfc_bytes_per_scan()

This helper function is a bit long to be inlined. Move it to the
source file and export it.

The mite driver is the only external user right now. Update the
Kconfig to select COMEDI_FC when COMEDI_MITE is enabled.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/Kconfig

@@ -1101,6 +1101,7 @@ config COMEDI_S626
 
 config COMEDI_MITE
 	depends on HAS_DMA
+	select COMEDI_FC
 	tristate
 
 config COMEDI_NI_TIOCMD

drivers/staging/comedi/drivers/comedi_fc.c

@@ -22,6 +22,28 @@
 
 #include "comedi_fc.h"
 
+unsigned int cfc_bytes_per_scan(struct comedi_subdevice *s)
+{
+	unsigned int chanlist_len = s->async->cmd.chanlist_len;
+	unsigned int num_samples;
+	unsigned int bits_per_sample;
+
+	switch (s->type) {
+	case COMEDI_SUBD_DI:
+	case COMEDI_SUBD_DO:
+	case COMEDI_SUBD_DIO:
+		bits_per_sample = 8 * bytes_per_sample(s);
+		num_samples = (chanlist_len + bits_per_sample - 1) /
+				bits_per_sample;
+		break;
+	default:
+		num_samples = chanlist_len;
+		break;
+	}
+	return num_samples * bytes_per_sample(s);
+}
+EXPORT_SYMBOL_GPL(cfc_bytes_per_scan);
+
 static void increment_scan_progress(struct comedi_subdevice *s,
 				    unsigned int num_bytes)
 {

drivers/staging/comedi/drivers/comedi_fc.h

@@ -23,6 +23,8 @@
 
 #include "../comedidev.h"
 
+unsigned int cfc_bytes_per_scan(struct comedi_subdevice *);
+
 /* Writes an array of data points to comedi's buffer */
 unsigned int cfc_write_array_to_buffer(struct comedi_subdevice *,
 				       void *data, unsigned int num_bytes);
@@ -45,27 +47,6 @@ unsigned int cfc_read_array_from_buffer(struct comedi_subdevice *,
 unsigned int cfc_handle_events(struct comedi_device *,
 			       struct comedi_subdevice *);
 
-static inline unsigned int cfc_bytes_per_scan(struct comedi_subdevice *s)
-{
-	unsigned int chanlist_len = s->async->cmd.chanlist_len;
-	unsigned int num_samples;
-	unsigned int bits_per_sample;
-
-	switch (s->type) {
-	case COMEDI_SUBD_DI:
-	case COMEDI_SUBD_DO:
-	case COMEDI_SUBD_DIO:
-		bits_per_sample = 8 * bytes_per_sample(s);
-		num_samples = (chanlist_len + bits_per_sample - 1) /
-				bits_per_sample;
-		break;
-	default:
-		num_samples = chanlist_len;
-		break;
-	}
-	return num_samples * bytes_per_sample(s);
-}
-
 /**
  * cfc_check_trigger_src() - trivially validate a comedi_cmd trigger source
  * @src: pointer to the trigger source to validate