staging: comedi: introduce comedi_range_is_{bi,uni}polar()

Introduce some helper functions to check if a given 'range' index
to a comedi_subdevice 'range_table' is a bipolar or unipolar range.

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

diff --git a/drivers/staging/comedi/comedidev.h b/drivers/staging/comedi/comedidev.h
index ab926a6654ef5062837c317e46cabf73f4911c06..57deabf77418dc2beac03eb03049f1b226369748 100644 (file)
--- a/drivers/staging/comedi/comedidev.h
+++ b/drivers/staging/comedi/comedidev.h
@@ -307,6 +307,18 @@ struct comedi_lrange {
        struct comedi_krange range[GCC_ZERO_LENGTH_ARRAY];
 };
 
+static inline bool comedi_range_is_bipolar(struct comedi_subdevice *s,
+                                          unsigned int range)
+{
+       return s->range_table->range[range].min < 0;
+}
+
+static inline bool comedi_range_is_unipolar(struct comedi_subdevice *s,
+                                           unsigned int range)
+{
+       return s->range_table->range[range].min >= 0;
+}
+
 /* some silly little inline functions */
 
 static inline unsigned int bytes_per_sample(const struct comedi_subdevice *subd)