diff --git a/Documentation/driver-api/device_connection.rst b/Documentation/driver-api/device_connection.rst
new file mode 100644
index 000000000000..64a3e5e9bb7c
--- /dev/null
+++ b/Documentation/driver-api/device_connection.rst
@@ -0,0 +1,43 @@
+==================
+Device connections
+==================
+
+Introduction
+------------
+
+Devices often have connections to other devices that are outside of the direct
+child/parent relationship. A serial or network communication controller, which
+could be a PCI device, may need to be able to get a reference to its PHY
+component, which could be attached for example to the I2C bus. Some device
+drivers need to be able to control the clocks or the GPIOs for their devices,
+and so on.
+
+Device connections are generic descriptions of any type of connection between
+two separate devices.
+
+Device connections alone do not create a dependency between the two devices.
+They are only descriptions which are not tied to either of the devices directly.
+A dependency between the two devices exists only if one of the two endpoint
+devices requests a reference to the other. The descriptions themselves can be
+defined in firmware (not yet supported) or they can be built-in.
+
+Usage
+-----
+
+Device connections should exist before device ``->probe`` callback is called for
+either endpoint device in the description. If the connections are defined in
+firmware, this is not a problem. It should be considered if the connection
+descriptions are "built-in", and need to be added separately.
+
+The connection description consists of the names of the two devices with the
+connection, i.e. the endpoints, and unique identifier for the connection which
+is needed if there are multiple connections between the two devices.
+
+After a description exists, the devices in it can request reference to the other
+endpoint device, or they can request the description itself.
+
+API
+---
+
+.. kernel-doc:: drivers/base/devcon.c
+   : functions: __device_find_connection device_find_connection add_device_connection remove_device_connection
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index e32a52490051..12a7f64d35a9 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -5,7 +5,8 @@ obj-y			:= component.o core.o bus.o dd.o syscore.o \
 			   driver.o class.o platform.o \
 			   cpu.o firmware.o init.o map.o devres.o \
 			   attribute_container.o transport_class.o \
-			   topology.o container.o property.o cacheinfo.o
+			   topology.o container.o property.o cacheinfo.o \
+			   devcon.o
 obj-$(CONFIG_DEVTMPFS)	+= devtmpfs.o
 obj-$(CONFIG_DMA_CMA) += dma-contiguous.o
 obj-y			+= power/
diff --git a/drivers/base/devcon.c b/drivers/base/devcon.c
new file mode 100644
index 000000000000..9f13092fa115
--- /dev/null
+++ b/drivers/base/devcon.c
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * Device connections
+ *
+ * Copyright (C) 2018 Intel Corporation
+ * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
+ */
+
+#include <linux/connection.h>
+#include <linux/device.h>
+
+static DEFINE_MUTEX(devcon_lock);
+static LIST_HEAD(devcon_list);
+
+/**
+ * __device_find_connection - 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_find_connection(struct device *dev, const char *con_id,
+			       void *data,
+			       void *(*match)(struct devcon *con, int ep,
+					      void *data))
+{
+	const char *devname = dev_name(dev);
+	struct devcon *con;
+	void *ret = NULL;
+	int ep;
+
+	if (!match)
+		return NULL;
+
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(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;
+	}
+
+	rcu_read_unlock();
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__device_find_connection);
+
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/i2c.h>
+#include <linux/pci.h>
+
+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,
+};
+
+/* This tries to find the device from the most common bus types by name. */
+static void *generic_match(struct devcon *con, int ep, void *data)
+{
+	struct bus_type *bus;
+	struct device *dev;
+
+	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_find_connection - 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_find_connection(struct device *dev, const char *con_id)
+{
+	return __device_find_connection(dev, con_id, NULL, generic_match);
+}
+EXPORT_SYMBOL_GPL(device_find_connection);
+
+/**
+ * add_device_connection - Register a collection of connection descriptions
+ * @con: Collection of connection descriptions to be registered
+ */
+void add_device_connection(struct devcon *con)
+{
+	mutex_lock(&devcon_lock);
+	list_add_tail_rcu(&con->list, &devcon_list);
+	mutex_unlock(&devcon_lock);
+}
+EXPORT_SYMBOL_GPL(add_device_connection);
+
+/**
+ * remove_device_connections - Unregister collection of connection descriptions
+ * @con: Collection of connection descriptions to be unregistered
+ */
+void remove_device_connection(struct devcon *con)
+{
+	mutex_lock(&devcon_lock);
+	list_del_rcu(&con->list);
+	mutex_unlock(&devcon_lock);
+	/* The caller may free the devcon struct immediately afterwards. */
+	synchronize_rcu();
+}
+EXPORT_SYMBOL_GPL(remove_device_connection);
diff --git a/include/linux/connection.h b/include/linux/connection.h
new file mode 100644
index 000000000000..b2af70df5a97
--- /dev/null
+++ b/include/linux/connection.h
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#ifndef _LINUX_CONNECTION_H_
+#define _LINUX_CONNECTION_H_
+
+#include <linux/list.h>
+
+struct device;
+
+/**
+ * struct devcon - Device Connection Descriptor
+ * @endpoint: The names of the two devices connected together
+ * @id: Unique identifier for the connection
+ * @list: List head, private for devcon internal use only
+ */
+struct devcon {
+	const char		*endpoint[2];
+	const char		*id;
+	struct list_head	list;
+};
+
+void *__device_find_connection(struct device *dev, const char *con_id,
+			       void *data,
+			       void *(*match)(struct devcon *con, int ep,
+					      void *data));
+
+struct device *device_find_connection(struct device *dev, const char *con_id);
+
+#define DEVCON(_ep0, _ep1, _id)    (struct devcon) { { _ep0, _ep1 }, _id, }
+
+void add_device_connection(struct devcon *con);
+void remove_device_connection(struct devcon *con);
+
+#endif /* _LINUX_CONNECTION_H_ */
