[PATCH v4 10/20] regulator: add REGULATOR_LINEAR_VRANGE macro

["André Draszik" <andre.draszik@linaro.org>]

REGULATOR_LINEAR_VRANGE is similar to REGULATOR_LINEAR_RANGE, but
allows a more natural declaration of a voltage range for a regulator,
in that it expects the minimum and maximum values as voltages rather
than as selectors.

Using voltages arguably makes this macro easier to use by drivers and
code using it can become easier to read compared to
REGULATOR_LINEAR_RANGE.

Signed-off-by: André Draszik <andre.draszik@linaro.org>

---
While this commit doesn't introduce any users, the upcoming s2mpg10 and
s2mpg11 drivers are using it.

v3:
- new patch
---
 include/linux/regulator/driver.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 978cf593b6624228fe1fd9c2a3e186b53ef172f8..977755db64c6dfaea7246067eab0d9a2971caa01 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -53,6 +53,11 @@ enum regulator_detection_severity {
 #define REGULATOR_LINEAR_RANGE(_min_uV, _min_sel, _max_sel, _step_uV)	\
 	LINEAR_RANGE(_min_uV, _min_sel, _max_sel, _step_uV)
 
+/* Initialize struct linear_range using voltages, not selectors */
+#define REGULATOR_LINEAR_VRANGE(_offs_uV, _min_uV, _max_uV, _step_uV)	\
+	LINEAR_RANGE(_min_uV, ((_min_uV) - (_offs_uV)) / (_step_uV),	\
+		     ((_max_uV) - (_offs_uV)) / (_step_uV), _step_uV)
+
 /**
  * struct regulator_ops - regulator operations.
  *

-- 
2.51.2.1041.gc1ab5b90ca-goog