ASR_BASE

Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/drivers/base/devcon.c b/marvell/linux/drivers/base/devcon.c
new file mode 100644
index 0000000..14e2178
--- /dev/null
+++ b/marvell/linux/drivers/base/devcon.c
@@ -0,0 +1,231 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * Device connections
+ *
+ * Copyright (C) 2018 Intel Corporation
+ * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
+ */
+
+#include <linux/device.h>
+#include <linux/property.h>
+
+static DEFINE_MUTEX(devcon_lock);
+static LIST_HEAD(devcon_list);
+
+static void *
+fwnode_graph_devcon_match(struct fwnode_handle *fwnode, const char *con_id,
+			  void *data, devcon_match_fn_t match)
+{
+	struct device_connection con = { .id = con_id };
+	struct fwnode_handle *ep;
+	void *ret;
+
+	fwnode_graph_for_each_endpoint(fwnode, ep) {
+		con.fwnode = fwnode_graph_get_remote_port_parent(ep);
+		if (!fwnode_device_is_available(con.fwnode))
+			continue;
+
+		ret = match(&con, -1, data);
+		fwnode_handle_put(con.fwnode);
+		if (ret) {
+			fwnode_handle_put(ep);
+			return ret;
+		}
+	}
+	return NULL;
+}
+
+static void *
+fwnode_devcon_match(struct fwnode_handle *fwnode, const char *con_id,
+		    void *data, devcon_match_fn_t match)
+{
+	struct device_connection con = { };
+	void *ret;
+	int i;
+
+	for (i = 0; ; i++) {
+		con.fwnode = fwnode_find_reference(fwnode, con_id, i);
+		if (IS_ERR(con.fwnode))
+			break;
+
+		ret = match(&con, -1, data);
+		fwnode_handle_put(con.fwnode);
+		if (ret)
+			return ret;
+	}
+
+	return NULL;
+}
+
+/**
+ * fwnode_connection_find_match - Find connection from a device node
+ * @fwnode: Device node with the connection
+ * @con_id: Identifier for the connection
+ * @data: Data for the match function
+ * @match: Function to check and convert the connection description
+ *
+ * Find a connection with unique identifier @con_id between @fwnode and another
+ * device node. @match will be used to convert the connection description to
+ * data the caller is expecting to be returned.
+ */
+void *fwnode_connection_find_match(struct fwnode_handle *fwnode,
+				   const char *con_id, void *data,
+				   devcon_match_fn_t match)
+{
+	void *ret;
+
+	if (!fwnode || !match)
+		return NULL;
+
+	ret = fwnode_graph_devcon_match(fwnode, con_id, data, match);
+	if (ret)
+		return ret;
+
+	return fwnode_devcon_match(fwnode, con_id, data, match);
+}
+EXPORT_SYMBOL_GPL(fwnode_connection_find_match);
+
+/**
+ * device_connection_find_match - Find physical connection to a device
+ * @dev: Device with the connection
+ * @con_id: Identifier for the connection
+ * @data: Data for the match function
+ * @match: Function to check and convert the connection description
+ *
+ * Find a connection with unique identifier @con_id between @dev and another
+ * device. @match will be used to convert the connection description to data the
+ * caller is expecting to be returned.
+ */
+void *device_connection_find_match(struct device *dev, const char *con_id,
+				   void *data, devcon_match_fn_t match)
+{
+	struct fwnode_handle *fwnode = dev_fwnode(dev);
+	const char *devname = dev_name(dev);
+	struct device_connection *con;
+	void *ret = NULL;
+	int ep;
+
+	if (!match)
+		return NULL;
+
+	ret = fwnode_connection_find_match(fwnode, con_id, data, match);
+	if (ret)
+		return ret;
+
+	mutex_lock(&devcon_lock);
+
+	list_for_each_entry(con, &devcon_list, list) {
+		ep = match_string(con->endpoint, 2, devname);
+		if (ep < 0)
+			continue;
+
+		if (con_id && strcmp(con->id, con_id))
+			continue;
+
+		ret = match(con, !ep, data);
+		if (ret)
+			break;
+	}
+
+	mutex_unlock(&devcon_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(device_connection_find_match);
+
+extern struct bus_type platform_bus_type;
+extern struct bus_type pci_bus_type;
+extern struct bus_type i2c_bus_type;
+extern struct bus_type spi_bus_type;
+
+static struct bus_type *generic_match_buses[] = {
+	&platform_bus_type,
+#ifdef CONFIG_PCI
+	&pci_bus_type,
+#endif
+#ifdef CONFIG_I2C
+	&i2c_bus_type,
+#endif
+#ifdef CONFIG_SPI_MASTER
+	&spi_bus_type,
+#endif
+	NULL,
+};
+
+static void *device_connection_fwnode_match(struct device_connection *con)
+{
+	struct bus_type *bus;
+	struct device *dev;
+
+	for (bus = generic_match_buses[0]; bus; bus++) {
+		dev = bus_find_device_by_fwnode(bus, con->fwnode);
+		if (dev && !strncmp(dev_name(dev), con->id, strlen(con->id)))
+			return dev;
+
+		put_device(dev);
+	}
+	return NULL;
+}
+
+/* This tries to find the device from the most common bus types by name. */
+static void *generic_match(struct device_connection *con, int ep, void *data)
+{
+	struct bus_type *bus;
+	struct device *dev;
+
+	if (con->fwnode)
+		return device_connection_fwnode_match(con);
+
+	for (bus = generic_match_buses[0]; bus; bus++) {
+		dev = bus_find_device_by_name(bus, NULL, con->endpoint[ep]);
+		if (dev)
+			return dev;
+	}
+
+	/*
+	 * We only get called if a connection was found, tell the caller to
+	 * wait for the other device to show up.
+	 */
+	return ERR_PTR(-EPROBE_DEFER);
+}
+
+/**
+ * device_connection_find - Find two devices connected together
+ * @dev: Device with the connection
+ * @con_id: Identifier for the connection
+ *
+ * Find a connection with unique identifier @con_id between @dev and
+ * another device. On success returns handle to the device that is connected
+ * to @dev, with the reference count for the found device incremented. Returns
+ * NULL if no matching connection was found, or ERR_PTR(-EPROBE_DEFER) when a
+ * connection was found but the other device has not been enumerated yet.
+ */
+struct device *device_connection_find(struct device *dev, const char *con_id)
+{
+	return device_connection_find_match(dev, con_id, NULL, generic_match);
+}
+EXPORT_SYMBOL_GPL(device_connection_find);
+
+/**
+ * device_connection_add - Register a connection description
+ * @con: The connection description to be registered
+ */
+void device_connection_add(struct device_connection *con)
+{
+	mutex_lock(&devcon_lock);
+	list_add_tail(&con->list, &devcon_list);
+	mutex_unlock(&devcon_lock);
+}
+EXPORT_SYMBOL_GPL(device_connection_add);
+
+/**
+ * device_connections_remove - Unregister connection description
+ * @con: The connection description to be unregistered
+ */
+void device_connection_remove(struct device_connection *con)
+{
+	mutex_lock(&devcon_lock);
+	list_del(&con->list);
+	mutex_unlock(&devcon_lock);
+}
+EXPORT_SYMBOL_GPL(device_connection_remove);