1 files changed, 123 insertions, 0 deletions
diff --git a/drivers/base/soc.c b/drivers/base/soc.c
new file mode 100644
index 0000000000..a481f8987b
--- /dev/null
+++ b/drivers/base/soc.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: 2024 Marco Felsch, Pengutronix
+/*
+ * Based on Linux drivers/base/soc.c:
+ * Copyright (C) ST-Ericsson SA 2011
+ */
+
+#include <common.h>
+#include <init.h>
+#include <of.h>
+
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+#include <linux/err.h>
+
+struct soc_device {
+	struct device dev;
+	struct soc_device_attribute *attr;
+};
+
+static struct bus_type soc_bus_type = {
+	.name  = "soc",
+};
+static bool soc_bus_registered;
+
+static void soc_device_add_params(struct soc_device *soc_dev)
+{
+	struct soc_device_attribute *attr = soc_dev->attr;
+	struct device *dev = &soc_dev->dev;
+
+	if (attr->machine)
+		dev_add_param_string_fixed(dev, "machine", attr->machine);
+	if (attr->family)
+		dev_add_param_string_fixed(dev, "family", attr->family);
+	if (attr->revision)
+		dev_add_param_string_fixed(dev, "revision", attr->revision);
+	if (attr->serial_number)
+		dev_add_param_string_fixed(dev, "serial_number", attr->serial_number);
+	if (attr->soc_id)
+		dev_add_param_string_fixed(dev, "soc_id", attr->soc_id);
+}
+
+static void soc_device_get_machine(struct soc_device_attribute *soc_dev_attr)
+{
+	struct device_node *np;
+
+	if (soc_dev_attr->machine)
+		return;
+
+	np = of_find_node_by_path("/");
+	of_property_read_string(np, "model", &soc_dev_attr->machine);
+	of_node_put(np);
+}
+
+static struct soc_device_attribute *early_soc_dev_attr;
+
+struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr)
+{
+	struct soc_device *soc_dev;
+	int ret;
+
+	soc_device_get_machine(soc_dev_attr);
+
+	if (!soc_bus_registered) {
+		if (early_soc_dev_attr)
+			return ERR_PTR(-EBUSY);
+		early_soc_dev_attr = soc_dev_attr;
+		return NULL;
+	}
+
+	soc_dev = kzalloc(sizeof(*soc_dev), GFP_KERNEL);
+	if (!soc_dev) {
+		ret = -ENOMEM;
+		goto out1;
+	}
+
+	soc_dev->attr = soc_dev_attr;
+	soc_dev->dev.bus = &soc_bus_type;
+	soc_dev->dev.id = DEVICE_ID_DYNAMIC;
+
+	dev_set_name(&soc_dev->dev, "soc");
+
+	ret = device_register(&soc_dev->dev);
+	if (ret) {
+		put_device(&soc_dev->dev);
+		goto out2;
+	}
+
+	soc_device_add_params(soc_dev);
+
+	return soc_dev;
+
+out2:
+	kfree(soc_dev);
+out1:
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(soc_device_register);
+
+/* Ensure soc_dev->attr is freed after calling soc_device_unregister. */
+void soc_device_unregister(struct soc_device *soc_dev)
+{
+	device_unregister(&soc_dev->dev);
+	kfree(soc_dev);
+	early_soc_dev_attr = NULL;
+}
+EXPORT_SYMBOL_GPL(soc_device_unregister);
+
+static int __init soc_bus_register(void)
+{
+	int ret;
+
+	ret = bus_register(&soc_bus_type);
+	if (ret)
+		return ret;
+	soc_bus_registered = true;
+
+	if (early_soc_dev_attr)
+		return PTR_ERR(soc_device_register(early_soc_dev_attr));
+
+	return 0;
+}
+core_initcall(soc_bus_register);