interconnect: qcom: Add multidev EPSS L3 support

EPSS on SA8775P has two instances, necessitating the creation of two
device nodes with different compatibles due to the unique ICC node ID
and name limitations in the interconnect framework. Add multidevice
support for the OSM-L3 provider to dynamically obtain unique node IDs
and register with the framework.
EPSS topology includes a single master-slave pair within the same
provider, the node linking logic is simplified by directly connecting
the master node to the slave node.

Signed-off-by: Raviteja Laggyshetty <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Georgi Djakov <[email protected]>

Author: Raviteja Laggyshetty

drivers/interconnect/qcom/osm-l3.c

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2025 Qualcomm Innovation Center, Inc. All rights reserved.
  */
 
 #include <linux/args.h>
@@ -32,8 +33,6 @@
 #define EPSS_REG_FREQ_LUT		0x100
 #define EPSS_REG_PERF_STATE		0x320
 
-#define OSM_L3_MAX_LINKS		1
-
 #define to_osm_l3_provider(_provider) \
 	container_of(_provider, struct qcom_osm_l3_icc_provider, provider)
 
@@ -48,16 +47,10 @@ struct qcom_osm_l3_icc_provider {
 /**
  * struct qcom_osm_l3_node - Qualcomm specific interconnect nodes
  * @name: the node name used in debugfs
- * @links: an array of nodes where we can go next while traversing
- * @id: a unique node identifier
- * @num_links: the total number of @links
  * @buswidth: width of the interconnect between a node and the bus
  */
 struct qcom_osm_l3_node {
 	const char *name;
-	u16 links[OSM_L3_MAX_LINKS];
-	u16 id;
-	u16 num_links;
 	u16 buswidth;
 };
 
@@ -69,30 +62,22 @@ struct qcom_osm_l3_desc {
 	unsigned int reg_perf_state;
 };
 
-enum {
-	OSM_L3_MASTER_NODE = 10000,
-	OSM_L3_SLAVE_NODE,
-};
-
-#define DEFINE_QNODE(_name, _id, _buswidth, ...)			\
+#define DEFINE_QNODE(_name, _buswidth)					\
 	static const struct qcom_osm_l3_node _name = {			\
 		.name = #_name,						\
-		.id = _id,						\
 		.buswidth = _buswidth,					\
-		.num_links = COUNT_ARGS(__VA_ARGS__),			\
-		.links = { __VA_ARGS__ },				\
 	}
 
-DEFINE_QNODE(osm_l3_master, OSM_L3_MASTER_NODE, 16, OSM_L3_SLAVE_NODE);
-DEFINE_QNODE(osm_l3_slave, OSM_L3_SLAVE_NODE, 16);
+DEFINE_QNODE(osm_l3_slave, 16);
+DEFINE_QNODE(osm_l3_master, 16);
 
 static const struct qcom_osm_l3_node * const osm_l3_nodes[] = {
 	[MASTER_OSM_L3_APPS] = &osm_l3_master,
 	[SLAVE_OSM_L3] = &osm_l3_slave,
 };
 
-DEFINE_QNODE(epss_l3_master, OSM_L3_MASTER_NODE, 32, OSM_L3_SLAVE_NODE);
-DEFINE_QNODE(epss_l3_slave, OSM_L3_SLAVE_NODE, 32);
+DEFINE_QNODE(epss_l3_slave, 32);
+DEFINE_QNODE(epss_l3_master, 32);
 
 static const struct qcom_osm_l3_node * const epss_l3_nodes[] = {
 	[MASTER_EPSS_L3_APPS] = &epss_l3_master,
@@ -242,10 +227,10 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
 
 	icc_provider_init(provider);
 
+	/* Create nodes */
 	for (i = 0; i < num_nodes; i++) {
-		size_t j;
+		node = icc_node_create_dyn();
 
-		node = icc_node_create(qnodes[i]->id);
 		if (IS_ERR(node)) {
 			ret = PTR_ERR(node);
 			goto err;
@@ -256,12 +241,12 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
 		node->data = (void *)qnodes[i];
 		icc_node_add(node, provider);
 
-		for (j = 0; j < qnodes[i]->num_links; j++)
-			icc_link_create(node, qnodes[i]->links[j]);
-
 		data->nodes[i] = node;
 	}
 
+	/* Create link */
+	icc_link_nodes(data->nodes[MASTER_OSM_L3_APPS], &data->nodes[SLAVE_OSM_L3]);
+
 	ret = icc_provider_register(provider);
 	if (ret)
 		goto err;
@@ -278,6 +263,7 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
 static const struct of_device_id osm_l3_of_match[] = {
 	{ .compatible = "qcom,epss-l3", .data = &epss_l3_l3_vote },
 	{ .compatible = "qcom,osm-l3", .data = &osm_l3 },
+	{ .compatible = "qcom,sa8775p-epss-l3", .data = &epss_l3_perf_state },
 	{ .compatible = "qcom,sc7180-osm-l3", .data = &osm_l3 },
 	{ .compatible = "qcom,sc7280-epss-l3", .data = &epss_l3_perf_state },
 	{ .compatible = "qcom,sdm845-osm-l3", .data = &osm_l3 },