interconnect: qcom: icc-rpm: Support multiple buckets

The current interconnect rpm driver uses a single aggregate bandwidth to
calculate the clock rates for both active and sleep clocks; therefore,
it has no chance to separate bandwidth requests for these two kinds of
clocks.

This patch studies the implementation from interconnect rpmh driver to
support multiple buckets. The rpmh driver provides three buckets for
AMC, WAKE, and SLEEP; this driver only needs to use WAKE and SLEEP
buckets, but we keep the same way with rpmh driver, this can allow us to
reuse the DT binding and avoid to define duplicated data structures.

This patch introduces two callbacks: qcom_icc_pre_bw_aggregate() is used
to clean up bucket values before aggregate bandwidth requests, and
qcom_icc_bw_aggregate() is to aggregate bandwidth for buckets.

Signed-off-by: Leo Yan <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Georgi Djakov <[e-mail]>

drivers/interconnect/qcom/icc-rpm.c

···
 	return 0;
 }
 
+/**
+ * qcom_icc_pre_bw_aggregate - cleans up values before re-aggregate requests
+ * @node: icc node to operate on
+ */
+static void qcom_icc_pre_bw_aggregate(struct icc_node *node)
+{
+	struct qcom_icc_node *qn;
+	size_t i;
+
+	qn = node->data;
+	for (i = 0; i < QCOM_ICC_NUM_BUCKETS; i++) {
+		qn->sum_avg[i] = 0;
+		qn->max_peak[i] = 0;
+	}
+}
+
+/**
+ * qcom_icc_bw_aggregate - aggregate bw for buckets indicated by tag
+ * @node: node to aggregate
+ * @tag: tag to indicate which buckets to aggregate
+ * @avg_bw: new bw to sum aggregate
+ * @peak_bw: new bw to max aggregate
+ * @agg_avg: existing aggregate avg bw val
+ * @agg_peak: existing aggregate peak bw val
+ */
+static int qcom_icc_bw_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
+				 u32 peak_bw, u32 *agg_avg, u32 *agg_peak)
+{
+	size_t i;
+	struct qcom_icc_node *qn;
+
+	qn = node->data;
+
+	if (!tag)
+		tag = QCOM_ICC_TAG_ALWAYS;
+
+	for (i = 0; i < QCOM_ICC_NUM_BUCKETS; i++) {
+		if (tag & BIT(i)) {
+			qn->sum_avg[i] += avg_bw;
+			qn->max_peak[i] = max_t(u32, qn->max_peak[i], peak_bw);
+		}
+	}
+
+	*agg_avg += avg_bw;
+	*agg_peak = max_t(u32, *agg_peak, peak_bw);
+	return 0;
+}
+
 static int qcom_icc_set(struct icc_node *src, struct icc_node *dst)
 {
 	struct qcom_icc_provider *qp;
···
 	INIT_LIST_HEAD(&provider->nodes);
 	provider->dev = dev;
 	provider->set = qcom_icc_set;
-	provider->aggregate = icc_std_aggregate;
+	provider->pre_aggregate = qcom_icc_pre_bw_aggregate;
+	provider->aggregate = qcom_icc_bw_aggregate;
 	provider->xlate_extended = qcom_icc_xlate_extended;
 	provider->data = data;
 

drivers/interconnect/qcom/icc-rpm.h

···
 #ifndef __DRIVERS_INTERCONNECT_QCOM_ICC_RPM_H
 #define __DRIVERS_INTERCONNECT_QCOM_ICC_RPM_H
 
+#include <dt-bindings/interconnect/qcom,icc.h>
+
 #define RPM_BUS_MASTER_REQ	0x73616d62
 #define RPM_BUS_SLAVE_REQ	0x766c7362
 
···
  * @links: an array of nodes where we can go next while traversing
  * @num_links: the total number of @links
  * @buswidth: width of the interconnect between a node and the bus (bytes)
+ * @sum_avg: current sum aggregate value of all avg bw requests
+ * @max_peak: current max aggregate value of all peak bw requests
  * @mas_rpm_id:	RPM id for devices that are bus masters
  * @slv_rpm_id:	RPM id for devices that are bus slaves
  * @qos: NoC QoS setting parameters
···
 	const u16 *links;
 	u16 num_links;
 	u16 buswidth;
+	u64 sum_avg[QCOM_ICC_NUM_BUCKETS];
+	u64 max_peak[QCOM_ICC_NUM_BUCKETS];
 	int mas_rpm_id;
 	int slv_rpm_id;
 	struct qcom_icc_qos qos;