From: Gene Chen <gene_chen@xxxxxxxxxxx>
Add linear range get selector within for choose closest selector
between minimum and maximum selector.
Signed-off-by: Gene Chen <gene_chen@xxxxxxxxxxx>
---
include/linux/linear_range.h | 2 ++
lib/linear_ranges.c | 31 +++++++++++++++++++++++++++++++
2 files changed, 33 insertions(+)
diff --git a/include/linux/linear_range.h b/include/linux/linear_range.h
index 17b5943727d5..fd3d0b358f22 100644
--- a/include/linux/linear_range.h
+++ b/include/linux/linear_range.h
@@ -41,6 +41,8 @@ int linear_range_get_selector_low(const struct linear_range *r,
int linear_range_get_selector_high(const struct linear_range *r,
unsigned int val, unsigned int *selector,
bool *found);
+void linear_range_get_selector_within(const struct linear_range *r,
+ unsigned int val, unsigned int *selector);
int linear_range_get_selector_low_array(const struct linear_range *r,
int ranges, unsigned int val,
unsigned int *selector, bool *found);
diff --git a/lib/linear_ranges.c b/lib/linear_ranges.c
index ced5c15d3f04..a1a7dfa881de 100644
--- a/lib/linear_ranges.c
+++ b/lib/linear_ranges.c
@@ -241,5 +241,36 @@ int linear_range_get_selector_high(const struct linear_range *r,
}
EXPORT_SYMBOL_GPL(linear_range_get_selector_high);
+/**
+ * linear_range_get_selector_within - return linear range selector for value
+ * @r: pointer to linear range where selector is looked from
+ * @val: value for which the selector is searched
+ * @selector: address where found selector value is updated
+ *
+ * Return selector for which range value is closest match for given
+ * input value. Value is matching if it is equal or lower than given
+ * value. But return maximum selector if given value is higher than
+ * maximum value.
+ */
+void linear_range_get_selector_within(const struct linear_range *r,
+ unsigned int val, unsigned int *selector)
+{
+ if (r->min > val) {
+ *selector = r->min_sel;
+ return;
+ }
+
+ if (linear_range_get_max_value(r) < val) {
+ *selector = r->max_sel;
+ return;
+ }
+
+ if (r->step == 0)
+ *selector = r->min_sel;
+ else
+ *selector = (val - r->min) / r->step + r->min_sel;
+}
+EXPORT_SYMBOL_GPL(linear_range_get_selector_within);
+
MODULE_DESCRIPTION("linear-ranges helper");
MODULE_LICENSE("GPL");
--
2.25.1
