lib: add linear range get selector within

Add linear range get selector within for choose closest selector
between minimum and maximum selector.

Signed-off-by: Gene Chen <gene_chen@richtek.com>
Reviewed-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

diff --git a/include/linux/linear_range.h b/include/linux/linear_range.h
index 17b5943..fd3d0b3 100644 (file)
--- 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 ced5c15..a1a7dfa 100644 (file)
--- 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");