interconnect: Add a common standard aggregate function

Currently there is one very standard aggregation method that is used by
several drivers. Let's add this as a common function, so that drivers
could just point to it, instead of copy/pasting code.
Suggested-by: Evan Green <evgreen@chromium.org>
Reviewed-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

drivers/interconnect/core.c

@@ -221,6 +221,16 @@ static int apply_constraints(struct icc_path *path)
 	return ret;
 }
 
+int icc_std_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
+		      u32 peak_bw, u32 *agg_avg, u32 *agg_peak)
+{
+	*agg_avg += avg_bw;
+	*agg_peak = max(*agg_peak, peak_bw);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(icc_std_aggregate);
+
 /* of_icc_xlate_onecell() - Translate function using a single index.
  * @spec: OF phandle args to map into an interconnect node.
  * @data: private data (pointer to struct icc_onecell_data)

include/linux/interconnect-provider.h

@@ -92,6 +92,8 @@ struct icc_node {
 
 #if IS_ENABLED(CONFIG_INTERCONNECT)
 
+int icc_std_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
+		      u32 peak_bw, u32 *agg_avg, u32 *agg_peak);
 struct icc_node *icc_node_create(int id);
 void icc_node_destroy(int id);
 int icc_link_create(struct icc_node *node, const int dst_id);
@@ -104,6 +106,12 @@ int icc_provider_del(struct icc_provider *provider);
 
 #else
 
+static inline int icc_std_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
+				    u32 peak_bw, u32 *agg_avg, u32 *agg_peak)
+{
+	return -ENOTSUPP;
+}
+
 static inline struct icc_node *icc_node_create(int id)
 {
 	return ERR_PTR(-ENOTSUPP);