new file mode 100644
@@ -0,0 +1,94 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=====================================
+GENERIC SYSTEM INTERCONNECT SUBSYSTEM
+=====================================
+
+Introduction
+------------
+
+This framework is designed to provide a standard kernel interface to control
+the settings of the interconnects on an SoC. These settings can be throughput,
+latency and priority between multiple interconnected devices or functional
+blocks. This can be controlled dynamically in order to save power or provide
+maximum performance.
+
+The interconnect bus is hardware with configurable parameters, which can be
+set on a data path according to the requests received from various drivers.
+An example of interconnect buses are the interconnects between various
+components or functional blocks in chipsets. There can be multiple interconnects
+on an SoC that can be multi-tiered.
+
+Below is a simplified diagram of a real-world SoC interconnect bus topology.
+
+::
+
+ +----------------+ +----------------+
+ | HW Accelerator |--->| M NoC |<---------------+
+ +----------------+ +----------------+ |
+ | | +------------+
+ +-----+ +-------------+ V +------+ | |
+ | DDR | | +--------+ | PCIe | | |
+ +-----+ | | Slaves | +------+ | |
+ ^ ^ | +--------+ | | C NoC |
+ | | V V | |
+ +------------------+ +------------------------+ | | +-----+
+ | |-->| |-->| |-->| CPU |
+ | |-->| |<--| | +-----+
+ | Mem NoC | | S NoC | +------------+
+ | |<--| |---------+ |
+ | |<--| |<------+ | | +--------+
+ +------------------+ +------------------------+ | | +-->| Slaves |
+ ^ ^ ^ ^ ^ | | +--------+
+ | | | | | | V
+ +------+ | +-----+ +-----+ +---------+ +----------------+ +--------+
+ | CPUs | | | GPU | | DSP | | Masters |-->| P NoC |-->| Slaves |
+ +------+ | +-----+ +-----+ +---------+ +----------------+ +--------+
+ |
+ +-------+
+ | Modem |
+ +-------+
+
+Terminology
+-----------
+
+Interconnect provider is the software definition of the interconnect hardware.
+The interconnect providers on the above diagram are M NoC, S NoC, C NoC, P NoC
+and Mem NoC.
+
+Interconnect node is the software definition of the interconnect hardware
+port. Each interconnect provider consists of multiple interconnect nodes,
+which are connected to other SoC components including other interconnect
+providers. The point on the diagram where the CPUs connect to the memory is
+called an interconnect node, which belongs to the Mem NoC interconnect provider.
+
+Interconnect endpoints are the first or the last element of the path. Every
+endpoint is a node, but not every node is an endpoint.
+
+Interconnect path is everything between two endpoints including all the nodes
+that have to be traversed to reach from a source to destination node. It may
+include multiple master-slave pairs across several interconnect providers.
+
+Interconnect consumers are the entities which make use of the data paths exposed
+by the providers. The consumers send requests to providers requesting various
+throughput, latency and priority. Usually the consumers are device drivers, that
+send request based on their needs. An example for a consumer is a video decoder
+that supports various formats and image sizes.
+
+Interconnect providers
+----------------------
+
+Interconnect provider is an entity that implements methods to initialize and
+configure interconnect bus hardware. The interconnect provider drivers should
+be registered with the interconnect provider core.
+
+.. kernel-doc:: include/linux/interconnect-provider.h
+
+Interconnect consumers
+----------------------
+
+Interconnect consumers are the clients which use the interconnect APIs to
+get paths between endpoints and set their bandwidth/latency/QoS requirements
+for these interconnect paths.
+
+.. kernel-doc:: include/linux/interconnect.h
@@ -219,4 +219,6 @@ source "drivers/siox/Kconfig"
source "drivers/slimbus/Kconfig"
+source "drivers/interconnect/Kconfig"
+
endmenu
@@ -186,3 +186,4 @@ obj-$(CONFIG_MULTIPLEXER) += mux/
obj-$(CONFIG_UNISYS_VISORBUS) += visorbus/
obj-$(CONFIG_SIOX) += siox/
obj-$(CONFIG_GNSS) += gnss/
+obj-$(CONFIG_INTERCONNECT) += interconnect/
new file mode 100644
@@ -0,0 +1,10 @@
+menuconfig INTERCONNECT
+ tristate "On-Chip Interconnect management support"
+ help
+ Support for management of the on-chip interconnects.
+
+ This framework is designed to provide a generic interface for
+ managing the interconnects in a SoC.
+
+ If unsure, say no.
+
new file mode 100644
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+
+icc-core-objs := core.o
+
+obj-$(CONFIG_INTERCONNECT) += icc-core.o
new file mode 100644
@@ -0,0 +1,567 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Interconnect framework core driver
+ *
+ * Copyright (c) 2018, Linaro Ltd.
+ * Author: Georgi Djakov <georgi.djakov@linaro.org>
+ */
+
+#include <linux/device.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/interconnect.h>
+#include <linux/interconnect-provider.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/overflow.h>
+
+static DEFINE_IDR(icc_idr);
+static LIST_HEAD(icc_providers);
+static DEFINE_MUTEX(icc_lock);
+
+/**
+ * struct icc_req - constraints that are attached to each node
+ * @req_node: entry in list of requests for the particular @node
+ * @node: the interconnect node to which this constraint applies
+ * @dev: reference to the device that sets the constraints
+ * @avg_bw: an integer describing the average bandwidth in kBps
+ * @peak_bw: an integer describing the peak bandwidth in kBps
+ */
+struct icc_req {
+ struct hlist_node req_node;
+ struct icc_node *node;
+ struct device *dev;
+ u32 avg_bw;
+ u32 peak_bw;
+};
+
+/**
+ * struct icc_path - interconnect path structure
+ * @num_nodes: number of hops (nodes)
+ * @reqs: array of the requests applicable to this path of nodes
+ */
+struct icc_path {
+ size_t num_nodes;
+ struct icc_req reqs[];
+};
+
+static struct icc_node *node_find(const int id)
+{
+ return idr_find(&icc_idr, id);
+}
+
+static struct icc_path *path_init(struct device *dev, struct icc_node *dst,
+ ssize_t num_nodes)
+{
+ struct icc_node *node = dst;
+ struct icc_path *path;
+ int i;
+
+ path = kzalloc(struct_size(path, reqs, num_nodes), GFP_KERNEL);
+ if (!path)
+ return ERR_PTR(-ENOMEM);
+
+ path->num_nodes = num_nodes;
+
+ for (i = num_nodes - 1; i >= 0; i--) {
+ node->provider->users++;
+ hlist_add_head(&path->reqs[i].req_node, &node->req_list);
+ path->reqs[i].node = node;
+ path->reqs[i].dev = dev;
+ /* reference to previous node was saved during path traversal */
+ node = node->reverse;
+ }
+
+ return path;
+}
+
+static struct icc_path *path_find(struct device *dev, struct icc_node *src,
+ struct icc_node *dst)
+{
+ struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
+ struct icc_node *n, *node = NULL;
+ struct list_head traverse_list;
+ struct list_head edge_list;
+ struct list_head visited_list;
+ size_t i, depth = 1;
+ bool found = false;
+
+ INIT_LIST_HEAD(&traverse_list);
+ INIT_LIST_HEAD(&edge_list);
+ INIT_LIST_HEAD(&visited_list);
+
+ list_add(&src->search_list, &traverse_list);
+ src->reverse = NULL;
+
+ do {
+ list_for_each_entry_safe(node, n, &traverse_list, search_list) {
+ if (node == dst) {
+ found = true;
+ list_splice_init(&edge_list, &visited_list);
+ list_splice_init(&traverse_list, &visited_list);
+ break;
+ }
+ for (i = 0; i < node->num_links; i++) {
+ struct icc_node *tmp = node->links[i];
+
+ if (!tmp) {
+ path = ERR_PTR(-ENOENT);
+ goto out;
+ }
+
+ if (tmp->is_traversed)
+ continue;
+
+ tmp->is_traversed = true;
+ tmp->reverse = node;
+ list_add_tail(&tmp->search_list, &edge_list);
+ }
+ }
+
+ if (found)
+ break;
+
+ list_splice_init(&traverse_list, &visited_list);
+ list_splice_init(&edge_list, &traverse_list);
+
+ /* count the hops including the source */
+ depth++;
+
+ } while (!list_empty(&traverse_list));
+
+out:
+
+ /* reset the traversed state */
+ list_for_each_entry_reverse(n, &visited_list, search_list)
+ n->is_traversed = false;
+
+ if (found)
+ path = path_init(dev, dst, depth);
+
+ return path;
+}
+
+/*
+ * We want the path to honor all bandwidth requests, so the average and peak
+ * bandwidth requirements from each consumer are aggregated at each node.
+ * The aggregation is platform specific, so each platform can customize it by
+ * implementing its own aggregate() function.
+ */
+
+static int aggregate_requests(struct icc_node *node)
+{
+ struct icc_provider *p = node->provider;
+ struct icc_req *r;
+
+ node->avg_bw = 0;
+ node->peak_bw = 0;
+
+ hlist_for_each_entry(r, &node->req_list, req_node)
+ p->aggregate(node, r->avg_bw, r->peak_bw,
+ &node->avg_bw, &node->peak_bw);
+
+ return 0;
+}
+
+static int apply_constraints(struct icc_path *path)
+{
+ struct icc_node *next, *prev = NULL;
+ int ret = -EINVAL;
+ int i;
+
+ for (i = 0; i < path->num_nodes; i++) {
+ next = path->reqs[i].node;
+
+ /*
+ * Both endpoints should be valid master-slave pairs of the
+ * same interconnect provider that will be configured.
+ */
+ if (!prev || next->provider != prev->provider) {
+ prev = next;
+ continue;
+ }
+
+ /* set the constraints */
+ ret = next->provider->set(prev, next);
+ if (ret)
+ goto out;
+
+ prev = next;
+ }
+out:
+ return ret;
+}
+
+/**
+ * icc_set() - set constraints on an interconnect path between two endpoints
+ * @path: reference to the path returned by icc_get()
+ * @avg_bw: average bandwidth in kilobytes per second
+ * @peak_bw: peak bandwidth in kilobytes per second
+ *
+ * This function is used by an interconnect consumer to express its own needs
+ * in terms of bandwidth for a previously requested path between two endpoints.
+ * The requests are aggregated and each node is updated accordingly. The entire
+ * path is locked by a mutex to ensure that the set() is completed.
+ * The @path can be NULL when the "interconnects" DT properties is missing,
+ * which will mean that no constraints will be set.
+ *
+ * Returns 0 on success, or an appropriate error code otherwise.
+ */
+int icc_set(struct icc_path *path, u32 avg_bw, u32 peak_bw)
+{
+ struct icc_node *node;
+ size_t i;
+ int ret;
+
+ if (!path)
+ return 0;
+
+ mutex_lock(&icc_lock);
+
+ for (i = 0; i < path->num_nodes; i++) {
+ node = path->reqs[i].node;
+
+ /* update the consumer request for this path */
+ path->reqs[i].avg_bw = avg_bw;
+ path->reqs[i].peak_bw = peak_bw;
+
+ /* aggregate requests for this node */
+ aggregate_requests(node);
+ }
+
+ ret = apply_constraints(path);
+ if (ret)
+ pr_debug("interconnect: error applying constraints (%d)\n",
+ ret);
+
+ mutex_unlock(&icc_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(icc_set);
+
+/**
+ * icc_get() - return a handle for path between two endpoints
+ * @dev: the device requesting the path
+ * @src_id: source device port id
+ * @dst_id: destination device port id
+ *
+ * This function will search for a path between two endpoints and return an
+ * icc_path handle on success. Use icc_put() to release
+ * constraints when they are not needed anymore.
+ * If the interconnect API is disabled, NULL is returned and the consumer
+ * drivers will still build. Drivers are free to handle this specifically,
+ * but they don't have to.
+ *
+ * Return: icc_path pointer on success, ERR_PTR() on error or NULL if the
+ * interconnect API is disabled.
+ */
+struct icc_path *icc_get(struct device *dev, const int src_id, const int dst_id)
+{
+ struct icc_node *src, *dst;
+ struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
+
+ mutex_lock(&icc_lock);
+
+ src = node_find(src_id);
+ if (!src)
+ goto out;
+
+ dst = node_find(dst_id);
+ if (!dst)
+ goto out;
+
+ path = path_find(dev, src, dst);
+ if (IS_ERR(path))
+ dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
+
+out:
+ mutex_unlock(&icc_lock);
+ return path;
+}
+EXPORT_SYMBOL_GPL(icc_get);
+
+/**
+ * icc_put() - release the reference to the icc_path
+ * @path: interconnect path
+ *
+ * Use this function to release the constraints on a path when the path is
+ * no longer needed. The constraints will be re-aggregated.
+ */
+void icc_put(struct icc_path *path)
+{
+ struct icc_node *node;
+ size_t i;
+ int ret;
+
+ if (!path || WARN_ON(IS_ERR(path)))
+ return;
+
+ ret = icc_set(path, 0, 0);
+ if (ret)
+ pr_err("%s: error (%d)\n", __func__, ret);
+
+ mutex_lock(&icc_lock);
+ for (i = 0; i < path->num_nodes; i++) {
+ node = path->reqs[i].node;
+ hlist_del(&path->reqs[i].req_node);
+ if (!WARN_ON(!node->provider->users))
+ node->provider->users--;
+ }
+ mutex_unlock(&icc_lock);
+
+ kfree(path);
+}
+EXPORT_SYMBOL_GPL(icc_put);
+
+static struct icc_node *icc_node_create_nolock(int id)
+{
+ struct icc_node *node;
+
+ /* check if node already exists */
+ node = node_find(id);
+ if (node)
+ return node;
+
+ node = kzalloc(sizeof(*node), GFP_KERNEL);
+ if (!node)
+ return ERR_PTR(-ENOMEM);
+
+ id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL);
+ if (id < 0) {
+ WARN(1, "%s: couldn't get idr\n", __func__);
+ kfree(node);
+ return ERR_PTR(id);
+ }
+
+ node->id = id;
+
+ return node;
+}
+
+/**
+ * icc_node_create() - create a node
+ * @id: node id
+ *
+ * Return: icc_node pointer on success, or ERR_PTR() on error
+ */
+struct icc_node *icc_node_create(int id)
+{
+ struct icc_node *node;
+
+ mutex_lock(&icc_lock);
+
+ node = icc_node_create_nolock(id);
+
+ mutex_unlock(&icc_lock);
+
+ return node;
+}
+EXPORT_SYMBOL_GPL(icc_node_create);
+
+/**
+ * icc_node_destroy() - destroy a node
+ * @id: node id
+ */
+void icc_node_destroy(int id)
+{
+ struct icc_node *node;
+
+ mutex_lock(&icc_lock);
+
+ node = node_find(id);
+ if (node) {
+ idr_remove(&icc_idr, node->id);
+ WARN_ON(!hlist_empty(&node->req_list));
+ }
+
+ mutex_unlock(&icc_lock);
+
+ kfree(node);
+}
+EXPORT_SYMBOL_GPL(icc_node_destroy);
+
+/**
+ * icc_link_create() - create a link between two nodes
+ * @node: source node id
+ * @dst_id: destination node id
+ *
+ * Create a link between two nodes. The nodes might belong to different
+ * interconnect providers and the @dst_id node might not exist (if the
+ * provider driver has not probed yet). So just create the @dst_id node
+ * and when the actual provider driver is probed, the rest of the node
+ * data is filled.
+ *
+ * Return: 0 on success, or an error code otherwise
+ */
+int icc_link_create(struct icc_node *node, const int dst_id)
+{
+ struct icc_node *dst;
+ struct icc_node **new;
+ int ret = 0;
+
+ if (!node->provider)
+ return -EINVAL;
+
+ mutex_lock(&icc_lock);
+
+ dst = node_find(dst_id);
+ if (!dst) {
+ dst = icc_node_create_nolock(dst_id);
+
+ if (IS_ERR(dst)) {
+ ret = PTR_ERR(dst);
+ goto out;
+ }
+ }
+
+ new = krealloc(node->links,
+ (node->num_links + 1) * sizeof(*node->links),
+ GFP_KERNEL);
+ if (!new) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ node->links = new;
+ node->links[node->num_links++] = dst;
+
+out:
+ mutex_unlock(&icc_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(icc_link_create);
+
+/**
+ * icc_link_destroy() - destroy a link between two nodes
+ * @src: pointer to source node
+ * @dst: pointer to destination node
+ *
+ * Return: 0 on success, or an error code otherwise
+ */
+int icc_link_destroy(struct icc_node *src, struct icc_node *dst)
+{
+ struct icc_node **new;
+ size_t slot;
+ int ret = 0;
+
+ if (IS_ERR_OR_NULL(src))
+ return -EINVAL;
+
+ if (IS_ERR_OR_NULL(dst))
+ return -EINVAL;
+
+ mutex_lock(&icc_lock);
+
+ for (slot = 0; slot < src->num_links; slot++)
+ if (src->links[slot] == dst)
+ break;
+
+ if (WARN_ON(slot == src->num_links)) {
+ ret = -ENXIO;
+ goto out;
+ }
+
+ src->links[slot] = src->links[--src->num_links];
+
+ new = krealloc(src->links, src->num_links * sizeof(*src->links),
+ GFP_KERNEL);
+ if (new)
+ src->links = new;
+
+out:
+ mutex_unlock(&icc_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(icc_link_destroy);
+
+/**
+ * icc_node_add() - add interconnect node to interconnect provider
+ * @node: pointer to the interconnect node
+ * @provider: pointer to the interconnect provider
+ */
+void icc_node_add(struct icc_node *node, struct icc_provider *provider)
+{
+ mutex_lock(&icc_lock);
+
+ node->provider = provider;
+ list_add_tail(&node->node_list, &provider->nodes);
+
+ mutex_unlock(&icc_lock);
+}
+EXPORT_SYMBOL_GPL(icc_node_add);
+
+/**
+ * icc_node_del() - delete interconnect node from interconnect provider
+ * @node: pointer to the interconnect node
+ */
+void icc_node_del(struct icc_node *node)
+{
+ mutex_lock(&icc_lock);
+
+ list_del(&node->node_list);
+
+ mutex_unlock(&icc_lock);
+}
+EXPORT_SYMBOL_GPL(icc_node_del);
+
+/**
+ * icc_provider_add() - add a new interconnect provider
+ * @provider: the interconnect provider that will be added into topology
+ *
+ * Return: 0 on success, or an error code otherwise
+ */
+int icc_provider_add(struct icc_provider *provider)
+{
+ if (WARN_ON(!provider->set))
+ return -EINVAL;
+
+ mutex_lock(&icc_lock);
+
+ INIT_LIST_HEAD(&provider->nodes);
+ list_add_tail(&provider->provider_list, &icc_providers);
+
+ mutex_unlock(&icc_lock);
+
+ dev_dbg(provider->dev, "interconnect provider added to topology\n");
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(icc_provider_add);
+
+/**
+ * icc_provider_del() - delete previously added interconnect provider
+ * @provider: the interconnect provider that will be removed from topology
+ *
+ * Return: 0 on success, or an error code otherwise
+ */
+int icc_provider_del(struct icc_provider *provider)
+{
+ mutex_lock(&icc_lock);
+ if (provider->users) {
+ pr_warn("interconnect provider still has %d users\n",
+ provider->users);
+ mutex_unlock(&icc_lock);
+ return -EBUSY;
+ }
+
+ if (!list_empty(&provider->nodes)) {
+ pr_warn("interconnect provider still has nodes\n");
+ mutex_unlock(&icc_lock);
+ return -EBUSY;
+ }
+
+ list_del(&provider->provider_list);
+ mutex_unlock(&icc_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(icc_provider_del);
+
+MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
+MODULE_DESCRIPTION("Interconnect Driver Core");
+MODULE_LICENSE("GPL v2");
new file mode 100644
@@ -0,0 +1,125 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2018, Linaro Ltd.
+ * Author: Georgi Djakov <georgi.djakov@linaro.org>
+ */
+
+#ifndef __LINUX_INTERCONNECT_PROVIDER_H
+#define __LINUX_INTERCONNECT_PROVIDER_H
+
+#include <linux/interconnect.h>
+
+#define icc_units_to_bps(bw) ((bw) * 1000ULL)
+
+struct icc_node;
+
+/**
+ * struct icc_provider - interconnect provider (controller) entity that might
+ * provide multiple interconnect controls
+ *
+ * @provider_list: list of the registered interconnect providers
+ * @nodes: internal list of the interconnect provider nodes
+ * @set: pointer to device specific set operation function
+ * @aggregate: pointer to device specific aggregate operation function
+ * @dev: the device this interconnect provider belongs to
+ * @users: count of active users
+ * @data: pointer to private data
+ */
+struct icc_provider {
+ struct list_head provider_list;
+ struct list_head nodes;
+ int (*set)(struct icc_node *src, struct icc_node *dst);
+ int (*aggregate)(struct icc_node *node, u32 avg_bw, u32 peak_bw,
+ u32 *agg_avg, u32 *agg_peak);
+ struct device *dev;
+ int users;
+ void *data;
+};
+
+/**
+ * struct icc_node - entity that is part of the interconnect topology
+ *
+ * @id: platform specific node id
+ * @name: node name used in debugfs
+ * @links: a list of targets pointing to where we can go next when traversing
+ * @num_links: number of links to other interconnect nodes
+ * @provider: points to the interconnect provider of this node
+ * @node_list: the list entry in the parent provider's "nodes" list
+ * @search_list: list used when walking the nodes graph
+ * @reverse: pointer to previous node when walking the nodes graph
+ * @is_traversed: flag that is used when walking the nodes graph
+ * @req_list: a list of QoS constraint requests associated with this node
+ * @avg_bw: aggregated value of average bandwidth requests from all consumers
+ * @peak_bw: aggregated value of peak bandwidth requests from all consumers
+ * @data: pointer to private data
+ */
+struct icc_node {
+ int id;
+ const char *name;
+ struct icc_node **links;
+ size_t num_links;
+
+ struct icc_provider *provider;
+ struct list_head node_list;
+ struct list_head search_list;
+ struct icc_node *reverse;
+ u8 is_traversed:1;
+ struct hlist_head req_list;
+ u32 avg_bw;
+ u32 peak_bw;
+ void *data;
+};
+
+#if IS_ENABLED(CONFIG_INTERCONNECT)
+
+struct icc_node *icc_node_create(int id);
+void icc_node_destroy(int id);
+int icc_link_create(struct icc_node *node, const int dst_id);
+int icc_link_destroy(struct icc_node *src, struct icc_node *dst);
+void icc_node_add(struct icc_node *node, struct icc_provider *provider);
+void icc_node_del(struct icc_node *node);
+int icc_provider_add(struct icc_provider *provider);
+int icc_provider_del(struct icc_provider *provider);
+
+#else
+
+static inline struct icc_node *icc_node_create(int id)
+{
+ return ERR_PTR(-ENOTSUPP);
+}
+
+void icc_node_destroy(int id)
+{
+}
+
+static inline int icc_link_create(struct icc_node *node, const int dst_id)
+{
+ return -ENOTSUPP;
+}
+
+int icc_link_destroy(struct icc_node *src, struct icc_node *dst)
+{
+ return -ENOTSUPP;
+}
+
+void icc_node_add(struct icc_node *node, struct icc_provider *provider)
+{
+}
+
+void icc_node_del(struct icc_node *node)
+{
+}
+
+static inline int icc_provider_add(struct icc_provider *provider)
+{
+ return -ENOTSUPP;
+}
+
+static inline int icc_provider_del(struct icc_provider *provider)
+{
+ return -ENOTSUPP;
+}
+
+#endif /* CONFIG_INTERCONNECT */
+
+#endif /* __LINUX_INTERCONNECT_PROVIDER_H */
new file mode 100644
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2018, Linaro Ltd.
+ * Author: Georgi Djakov <georgi.djakov@linaro.org>
+ */
+
+#ifndef __LINUX_INTERCONNECT_H
+#define __LINUX_INTERCONNECT_H
+
+#include <linux/mutex.h>
+#include <linux/types.h>
+
+/* macros for converting to icc units */
+#define Bps_to_icc(x) ((x) / 1000)
+#define kBps_to_icc(x) (x)
+#define MBps_to_icc(x) ((x) * 1000)
+#define GBps_to_icc(x) ((x) * 1000 * 1000)
+#define bps_to_icc(x) (1)
+#define kbps_to_icc(x) ((x) / 8 + ((x) % 8 ? 1 : 0))
+#define Mbps_to_icc(x) ((x) * 1000 / 8)
+#define Gbps_to_icc(x) ((x) * 1000 * 1000 / 8)
+
+struct icc_path;
+struct device;
+
+#if IS_ENABLED(CONFIG_INTERCONNECT)
+
+struct icc_path *icc_get(struct device *dev, const int src_id,
+ const int dst_id);
+void icc_put(struct icc_path *path);
+int icc_set(struct icc_path *path, u32 avg_bw, u32 peak_bw);
+
+#else
+
+static inline struct icc_path *icc_get(struct device *dev, const int src_id,
+ const int dst_id)
+{
+ return NULL;
+}
+
+static inline void icc_put(struct icc_path *path)
+{
+}
+
+static inline int icc_set(struct icc_path *path, u32 avg_bw, u32 peak_bw)
+{
+ return 0;
+}
+
+#endif /* CONFIG_INTERCONNECT */
+
+#endif /* __LINUX_INTERCONNECT_H */