staging: comedi: add comedi_inc_scan_progress()

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_inc_scan_progress()` into the core comedi module
and rename it to `comedi_inc_scan_progress()`.  Change the external
declaration of `cfc_inc_scan_progress()` into an inline function that
calls `comedi_inc_scan_progress()`.

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>

drivers/staging/comedi/comedidev.h

@@ -443,6 +443,8 @@ int comedi_dio_insn_config(struct comedi_device *, struct comedi_subdevice *,
 unsigned int comedi_dio_update_state(struct comedi_subdevice *,
 				     unsigned int *data);
 unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s);
+void comedi_inc_scan_progress(struct comedi_subdevice *s,
+			      unsigned int num_bytes);
 
 void *comedi_alloc_devpriv(struct comedi_device *, size_t);
 int comedi_alloc_subdevices(struct comedi_device *, int);

drivers/staging/comedi/drivers.c

@@ -327,6 +327,30 @@ unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s)
 }
 EXPORT_SYMBOL_GPL(comedi_bytes_per_scan);
 
+/**
+ * comedi_inc_scan_progress - update scan progress in asynchronous command
+ * @s: comedi_subdevice struct
+ * @num_bytes: amount of data in bytes to increment scan progress
+ *
+ * Increments the scan progress by the number of bytes specified by num_bytes.
+ * If the scan progress reaches or exceeds the scan length in bytes, reduce
+ * it modulo the scan length in bytes and set the "end of scan" asynchronous
+ * event flag to be processed later.
+ */
+void comedi_inc_scan_progress(struct comedi_subdevice *s,
+			      unsigned int num_bytes)
+{
+	struct comedi_async *async = s->async;
+	unsigned int scan_length = comedi_bytes_per_scan(s);
+
+	async->scan_progress += num_bytes;
+	if (async->scan_progress >= scan_length) {
+		async->scan_progress %= scan_length;
+		async->events |= COMEDI_CB_EOS;
+	}
+}
+EXPORT_SYMBOL_GPL(comedi_inc_scan_progress);
+
 static int insn_rw_emulate_bits(struct comedi_device *dev,
 				struct comedi_subdevice *s,
 				struct comedi_insn *insn, unsigned int *data)

drivers/staging/comedi/drivers/comedi_fc.c

@@ -22,19 +22,6 @@
 
 #include "comedi_fc.h"
 
-void cfc_inc_scan_progress(struct comedi_subdevice *s, unsigned int num_bytes)
-{
-	struct comedi_async *async = s->async;
-	unsigned int scan_length = comedi_bytes_per_scan(s);
-
-	async->scan_progress += num_bytes;
-	if (async->scan_progress >= scan_length) {
-		async->scan_progress %= scan_length;
-		async->events |= COMEDI_CB_EOS;
-	}
-}
-EXPORT_SYMBOL_GPL(cfc_inc_scan_progress);
-
 /* Writes an array of data points to comedi's buffer */
 unsigned int cfc_write_array_to_buffer(struct comedi_subdevice *s,
 				       void *data, unsigned int num_bytes)

drivers/staging/comedi/drivers/comedi_fc.h

@@ -28,7 +28,11 @@ static inline unsigned int cfc_bytes_per_scan(struct comedi_subdevice *s)
 	return comedi_bytes_per_scan(s);
 }
 
-void cfc_inc_scan_progress(struct comedi_subdevice *, unsigned int num_bytes);
+static inline void cfc_inc_scan_progress(struct comedi_subdevice *s,
+					 unsigned int num_bytes)
+{
+	comedi_inc_scan_progress(s, num_bytes);
+}
 
 /* Writes an array of data points to comedi's buffer */
 unsigned int cfc_write_array_to_buffer(struct comedi_subdevice *,