remoteproc: mediatek: Probe SCP cluster on multi-core SCP

The difference of single-core SCP and multi-core SCP device tree is
the presence of child device nodes described SCP cores. The SCP
driver populates the platform device and checks the child nodes
to identify whether it's a single-core SCP or a multi-core SCP.

Add the remoteproc instances of multi-core SCP to the SCP cluster list.
When the SCP driver is removed, it cleanup resources by walking
through the cluster list.
Signed-off-by: Tinghan Shen <tinghan.shen@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20230901080935.14571-9-tinghan.shen@mediatek.comSigned-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

drivers/remoteproc/mtk_scp.c

@@ -855,7 +855,8 @@ static void scp_remove_rpmsg_subdev(struct mtk_scp *scp)
 }
 
 static struct mtk_scp *scp_rproc_init(struct platform_device *pdev,
-				      struct mtk_scp_of_cluster *scp_cluster)
+				      struct mtk_scp_of_cluster *scp_cluster,
+				      const struct mtk_scp_of_data *of_data)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
@@ -878,7 +879,7 @@ static struct mtk_scp *scp_rproc_init(struct platform_device *pdev,
 	scp = rproc->priv;
 	scp->rproc = rproc;
 	scp->dev = dev;
-	scp->data = of_device_get_match_data(dev);
+	scp->data = of_data;
 	scp->cluster = scp_cluster;
 	platform_set_drvdata(pdev, scp);
 
@@ -951,7 +952,7 @@ static void scp_free(struct mtk_scp *scp)
 	mutex_destroy(&scp->send_lock);
 }
 
-static int scp_cluster_init(struct platform_device *pdev,
+static int scp_add_single_core(struct platform_device *pdev,
 			       struct mtk_scp_of_cluster *scp_cluster)
 {
 	struct device *dev = &pdev->dev;
@@ -959,7 +960,7 @@ static int scp_cluster_init(struct platform_device *pdev,
 	struct mtk_scp *scp;
 	int ret;
 
-	scp = scp_rproc_init(pdev, scp_cluster);
+	scp = scp_rproc_init(pdev, scp_cluster, of_device_get_match_data(dev));
 	if (IS_ERR(scp))
 		return PTR_ERR(scp);
 
@@ -975,6 +976,108 @@ static int scp_cluster_init(struct platform_device *pdev,
 	return 0;
 }
 
+static int scp_add_multi_core(struct platform_device *pdev,
+			      struct mtk_scp_of_cluster *scp_cluster)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev_of_node(dev);
+	struct platform_device *cpdev;
+	struct device_node *child;
+	struct list_head *scp_list = &scp_cluster->mtk_scp_list;
+	const struct mtk_scp_of_data **cluster_of_data;
+	struct mtk_scp *scp, *temp;
+	int core_id = 0;
+	int ret;
+
+	cluster_of_data = (const struct mtk_scp_of_data **)of_device_get_match_data(dev);
+
+	for_each_available_child_of_node(np, child) {
+		if (!cluster_of_data[core_id]) {
+			ret = -EINVAL;
+			dev_err(dev, "Not support core %d\n", core_id);
+			of_node_put(child);
+			goto init_fail;
+		}
+
+		cpdev = of_find_device_by_node(child);
+		if (!cpdev) {
+			ret = -ENODEV;
+			dev_err(dev, "Not found platform device for core %d\n", core_id);
+			of_node_put(child);
+			goto init_fail;
+		}
+
+		scp = scp_rproc_init(cpdev, scp_cluster, cluster_of_data[core_id]);
+		put_device(&cpdev->dev);
+		if (IS_ERR(scp)) {
+			ret = PTR_ERR(scp);
+			dev_err(dev, "Failed to initialize core %d rproc\n", core_id);
+			of_node_put(child);
+			goto init_fail;
+		}
+
+		ret = rproc_add(scp->rproc);
+		if (ret) {
+			dev_err(dev, "Failed to add rproc of core %d\n", core_id);
+			of_node_put(child);
+			scp_free(scp);
+			goto init_fail;
+		}
+
+		list_add_tail(&scp->elem, scp_list);
+		core_id++;
+	}
+
+	/*
+	 * Here we are setting the platform device for @pdev to the last @scp that was
+	 * created, which is needed because (1) scp_rproc_init() is calling
+	 * platform_set_drvdata() on the child platform devices and (2) we need a handle to
+	 * the cluster list in scp_remove().
+	 */
+	platform_set_drvdata(pdev, scp);
+
+	return 0;
+
+init_fail:
+	list_for_each_entry_safe_reverse(scp, temp, scp_list, elem) {
+		list_del(&scp->elem);
+		rproc_del(scp->rproc);
+		scp_free(scp);
+	}
+
+	return ret;
+}
+
+static int scp_is_single_core(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev_of_node(dev);
+	struct device_node *child;
+
+	child = of_get_next_available_child(np, NULL);
+	if (!child)
+		return dev_err_probe(dev, -ENODEV, "No child node\n");
+
+	of_node_put(child);
+	return of_node_name_eq(child, "cros-ec-rpmsg");
+}
+
+static int scp_cluster_init(struct platform_device *pdev, struct mtk_scp_of_cluster *scp_cluster)
+{
+	int ret;
+
+	ret = scp_is_single_core(pdev);
+	if (ret < 0)
+		return ret;
+
+	if (ret)
+		ret = scp_add_single_core(pdev, scp_cluster);
+	else
+		ret = scp_add_multi_core(pdev, scp_cluster);
+
+	return ret;
+}
+
 static int scp_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -1007,6 +1110,10 @@ static int scp_probe(struct platform_device *pdev)
 
 	INIT_LIST_HEAD(&scp_cluster->mtk_scp_list);
 
+	ret = devm_of_platform_populate(dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to populate platform devices\n");
+
 	ret = scp_cluster_init(pdev, scp_cluster);
 	if (ret)
 		return ret;
@@ -1101,12 +1208,19 @@ static const struct mtk_scp_of_data mt8195_of_data_c1 = {
 	.host_to_scp_int_bit = MT8195_CORE1_HOST_IPC_INT_BIT,
 };
 
+static const struct mtk_scp_of_data *mt8195_of_data_cores[] = {
+	&mt8195_of_data,
+	&mt8195_of_data_c1,
+	NULL
+};
+
 static const struct of_device_id mtk_scp_of_match[] = {
 	{ .compatible = "mediatek,mt8183-scp", .data = &mt8183_of_data },
 	{ .compatible = "mediatek,mt8186-scp", .data = &mt8186_of_data },
 	{ .compatible = "mediatek,mt8188-scp", .data = &mt8188_of_data },
 	{ .compatible = "mediatek,mt8192-scp", .data = &mt8192_of_data },
 	{ .compatible = "mediatek,mt8195-scp", .data = &mt8195_of_data },
+	{ .compatible = "mediatek,mt8195-scp-dual", .data = &mt8195_of_data_cores },
 	{},
 };
 MODULE_DEVICE_TABLE(of, mtk_scp_of_match);