Linux 6.13-rc6

[linux.git] / drivers / hwtracing / coresight / coresight-platform.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2012, The Linux Foundation. All rights reserved.
 */

#include <linux/acpi.h>
#include <linux/types.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/of_graph.h>
#include <linux/platform_device.h>
#include <linux/amba/bus.h>
#include <linux/coresight.h>
#include <linux/cpumask.h>
#include <asm/smp_plat.h>

#include "coresight-priv.h"

/*
 * Add an entry to the connection list and assign @conn's contents to it.
 *
 * If the output port is already assigned on this device, return -EINVAL
 */
struct coresight_connection *
coresight_add_out_conn(struct device *dev,
                       struct coresight_platform_data *pdata,
                       const struct coresight_connection *new_conn)
{
        int i;
        struct coresight_connection *conn;

        /*
         * Warn on any existing duplicate output port.
         */
        for (i = 0; i < pdata->nr_outconns; ++i) {
                conn = pdata->out_conns[i];
                /* Output == -1 means ignore the port for example for helpers */
                if (conn->src_port != -1 &&
                    conn->src_port == new_conn->src_port) {
                        dev_warn(dev, "Duplicate output port %d\n",
                                 conn->src_port);
                        return ERR_PTR(-EINVAL);
                }
        }

        pdata->nr_outconns++;
        pdata->out_conns =
                devm_krealloc_array(dev, pdata->out_conns, pdata->nr_outconns,
                                    sizeof(*pdata->out_conns), GFP_KERNEL);
        if (!pdata->out_conns)
                return ERR_PTR(-ENOMEM);

        conn = devm_kmalloc(dev, sizeof(struct coresight_connection),
                            GFP_KERNEL);
        if (!conn)
                return ERR_PTR(-ENOMEM);

        /*
         * Copy the new connection into the allocation, save the pointer to the
         * end of the connection array and also return it in case it needs to be
         * used right away.
         */
        *conn = *new_conn;
        pdata->out_conns[pdata->nr_outconns - 1] = conn;
        return conn;
}
EXPORT_SYMBOL_GPL(coresight_add_out_conn);

/*
 * Add an input connection reference to @out_conn in the target's in_conns array
 *
 * @out_conn: Existing output connection to store as an input on the
 *            connection's remote device.
 */
int coresight_add_in_conn(struct coresight_connection *out_conn)
{
        int i;
        struct device *dev = out_conn->dest_dev->dev.parent;
        struct coresight_platform_data *pdata = out_conn->dest_dev->pdata;

        for (i = 0; i < pdata->nr_inconns; ++i)
                if (!pdata->in_conns[i]) {
                        pdata->in_conns[i] = out_conn;
                        return 0;
                }

        pdata->nr_inconns++;
        pdata->in_conns =
                devm_krealloc_array(dev, pdata->in_conns, pdata->nr_inconns,
                                    sizeof(*pdata->in_conns), GFP_KERNEL);
        if (!pdata->in_conns)
                return -ENOMEM;
        pdata->in_conns[pdata->nr_inconns - 1] = out_conn;
        return 0;
}
EXPORT_SYMBOL_GPL(coresight_add_in_conn);

static struct device *
coresight_find_device_by_fwnode(struct fwnode_handle *fwnode)
{
        struct device *dev = NULL;

        /*
         * If we have a non-configurable replicator, it will be found on the
         * platform bus.
         */
        dev = bus_find_device_by_fwnode(&platform_bus_type, fwnode);
        if (dev)
                return dev;

        /*
         * We have a configurable component - circle through the AMBA bus
         * looking for the device that matches the endpoint node.
         */
        return bus_find_device_by_fwnode(&amba_bustype, fwnode);
}

/*
 * Find a registered coresight device from a device fwnode.
 * The node info is associated with the AMBA parent, but the
 * csdev keeps a copy so iterate round the coresight bus to
 * find the device.
 */
struct coresight_device *
coresight_find_csdev_by_fwnode(struct fwnode_handle *r_fwnode)
{
        struct device *dev;
        struct coresight_device *csdev = NULL;

        dev = bus_find_device_by_fwnode(&coresight_bustype, r_fwnode);
        if (dev) {
                csdev = to_coresight_device(dev);
                put_device(dev);
        }
        return csdev;
}
EXPORT_SYMBOL_GPL(coresight_find_csdev_by_fwnode);

#ifdef CONFIG_OF
static inline bool of_coresight_legacy_ep_is_input(struct device_node *ep)
{
        return of_property_read_bool(ep, "slave-mode");
}

static struct device_node *of_coresight_get_port_parent(struct device_node *ep)
{
        struct device_node *parent = of_graph_get_port_parent(ep);

        /*
         * Skip one-level up to the real device node, if we
         * are using the new bindings.
         */
        if (of_node_name_eq(parent, "in-ports") ||
            of_node_name_eq(parent, "out-ports"))
                parent = of_get_next_parent(parent);

        return parent;
}

static inline struct device_node *
of_coresight_get_output_ports_node(const struct device_node *node)
{
        return of_get_child_by_name(node, "out-ports");
}

static int of_coresight_get_cpu(struct device *dev)
{
        int cpu;
        struct device_node *dn;

        if (!dev->of_node)
                return -ENODEV;

        dn = of_parse_phandle(dev->of_node, "cpu", 0);
        if (!dn)
                return -ENODEV;

        cpu = of_cpu_node_to_id(dn);
        of_node_put(dn);

        return cpu;
}

/*
 * of_coresight_parse_endpoint : Parse the given output endpoint @ep
 * and fill the connection information in @pdata->out_conns
 *
 * Parses the local port, remote device name and the remote port.
 *
 * Returns :
 *       0      - If the parsing completed without any fatal errors.
 *      -Errno  - Fatal error, abort the scanning.
 */
static int of_coresight_parse_endpoint(struct device *dev,
                                       struct device_node *ep,
                                       struct coresight_platform_data *pdata)
{
        int ret = 0;
        struct of_endpoint endpoint, rendpoint;
        struct device_node *rparent = NULL;
        struct device_node *rep = NULL;
        struct device *rdev = NULL;
        struct fwnode_handle *rdev_fwnode;
        struct coresight_connection conn = {};
        struct coresight_connection *new_conn;

        do {
                /* Parse the local port details */
                if (of_graph_parse_endpoint(ep, &endpoint))
                        break;
                /*
                 * Get a handle on the remote endpoint and the device it is
                 * attached to.
                 */
                rep = of_graph_get_remote_endpoint(ep);
                if (!rep)
                        break;
                rparent = of_coresight_get_port_parent(rep);
                if (!rparent)
                        break;
                if (of_graph_parse_endpoint(rep, &rendpoint))
                        break;

                rdev_fwnode = of_fwnode_handle(rparent);
                /* If the remote device is not available, defer probing */
                rdev = coresight_find_device_by_fwnode(rdev_fwnode);
                if (!rdev) {
                        ret = -EPROBE_DEFER;
                        break;
                }

                conn.src_port = endpoint.port;
                /*
                 * Hold the refcount to the target device. This could be
                 * released via:
                 * 1) coresight_release_platform_data() if the probe fails or
                 *    this device is unregistered.
                 * 2) While removing the target device via
                 *    coresight_remove_match()
                 */
                conn.dest_fwnode = fwnode_handle_get(rdev_fwnode);
                conn.dest_port = rendpoint.port;

                new_conn = coresight_add_out_conn(dev, pdata, &conn);
                if (IS_ERR_VALUE(new_conn)) {
                        fwnode_handle_put(conn.dest_fwnode);
                        return PTR_ERR(new_conn);
                }
                /* Connection record updated */
        } while (0);

        of_node_put(rparent);
        of_node_put(rep);
        put_device(rdev);

        return ret;
}

static int of_get_coresight_platform_data(struct device *dev,
                                          struct coresight_platform_data *pdata)
{
        int ret = 0;
        struct device_node *ep = NULL;
        const struct device_node *parent = NULL;
        bool legacy_binding = false;
        struct device_node *node = dev->of_node;

        parent = of_coresight_get_output_ports_node(node);
        /*
         * If the DT uses obsoleted bindings, the ports are listed
         * under the device and we need to filter out the input
         * ports.
         */
        if (!parent) {
                /*
                 * Avoid warnings in for_each_endpoint_of_node()
                 * if the device doesn't have any graph connections
                 */
                if (!of_graph_is_present(node))
                        return 0;
                legacy_binding = true;
                parent = node;
                dev_warn_once(dev, "Uses obsolete Coresight DT bindings\n");
        }

        /* Iterate through each output port to discover topology */
        for_each_endpoint_of_node(parent, ep) {
                /*
                 * Legacy binding mixes input/output ports under the
                 * same parent. So, skip the input ports if we are dealing
                 * with legacy binding, as they processed with their
                 * connected output ports.
                 */
                if (legacy_binding && of_coresight_legacy_ep_is_input(ep))
                        continue;

                ret = of_coresight_parse_endpoint(dev, ep, pdata);
                if (ret) {
                        of_node_put(ep);
                        return ret;
                }
        }

        return 0;
}
#else
static inline int
of_get_coresight_platform_data(struct device *dev,
                               struct coresight_platform_data *pdata)
{
        return -ENOENT;
}

static inline int of_coresight_get_cpu(struct device *dev)
{
        return -ENODEV;
}
#endif

#ifdef CONFIG_ACPI

#include <acpi/actypes.h>
#include <acpi/processor.h>

/* ACPI Graph _DSD UUID : "ab02a46b-74c7-45a2-bd68-f7d344ef2153" */
static const guid_t acpi_graph_uuid = GUID_INIT(0xab02a46b, 0x74c7, 0x45a2,
                                                0xbd, 0x68, 0xf7, 0xd3,
                                                0x44, 0xef, 0x21, 0x53);
/* Coresight ACPI Graph UUID : "3ecbc8b6-1d0e-4fb3-8107-e627f805c6cd" */
static const guid_t coresight_graph_uuid = GUID_INIT(0x3ecbc8b6, 0x1d0e, 0x4fb3,
                                                     0x81, 0x07, 0xe6, 0x27,
                                                     0xf8, 0x05, 0xc6, 0xcd);
#define ACPI_CORESIGHT_LINK_SLAVE       0
#define ACPI_CORESIGHT_LINK_MASTER      1

static inline bool is_acpi_guid(const union acpi_object *obj)
{
        return (obj->type == ACPI_TYPE_BUFFER) && (obj->buffer.length == 16);
}

/*
 * acpi_guid_matches    - Checks if the given object is a GUID object and
 * that it matches the supplied the GUID.
 */
static inline bool acpi_guid_matches(const union acpi_object *obj,
                                   const guid_t *guid)
{
        return is_acpi_guid(obj) &&
               guid_equal((guid_t *)obj->buffer.pointer, guid);
}

static inline bool is_acpi_dsd_graph_guid(const union acpi_object *obj)
{
        return acpi_guid_matches(obj, &acpi_graph_uuid);
}

static inline bool is_acpi_coresight_graph_guid(const union acpi_object *obj)
{
        return acpi_guid_matches(obj, &coresight_graph_uuid);
}

static inline bool is_acpi_coresight_graph(const union acpi_object *obj)
{
        const union acpi_object *graphid, *guid, *links;

        if (obj->type != ACPI_TYPE_PACKAGE ||
            obj->package.count < 3)
                return false;

        graphid = &obj->package.elements[0];
        guid = &obj->package.elements[1];
        links = &obj->package.elements[2];

        if (graphid->type != ACPI_TYPE_INTEGER ||
            links->type != ACPI_TYPE_INTEGER)
                return false;

        return is_acpi_coresight_graph_guid(guid);
}

/*
 * acpi_validate_dsd_graph      - Make sure the given _DSD graph conforms
 * to the ACPI _DSD Graph specification.
 *
 * ACPI Devices Graph property has the following format:
 *  {
 *      Revision        - Integer, must be 0
 *      NumberOfGraphs  - Integer, N indicating the following list.
 *      Graph[1],
 *       ...
 *      Graph[N]
 *  }
 *
 * And each Graph entry has the following format:
 *  {
 *      GraphID         - Integer, identifying a graph the device belongs to.
 *      UUID            - UUID identifying the specification that governs
 *                        this graph. (e.g, see is_acpi_coresight_graph())
 *      NumberOfLinks   - Number "N" of connections on this node of the graph.
 *      Links[1]
 *      ...
 *      Links[N]
 *  }
 *
 * Where each "Links" entry has the following format:
 *
 * {
 *      SourcePortAddress       - Integer
 *      DestinationPortAddress  - Integer
 *      DestinationDeviceName   - Reference to another device
 *      ( --- CoreSight specific extensions below ---)
 *      DirectionOfFlow         - Integer 1 for output(master)
 *                                0 for input(slave)
 * }
 *
 * e.g:
 * For a Funnel device
 *
 * Device(MFUN) {
 *   ...
 *
 *   Name (_DSD, Package() {
 *      // DSD Package contains tuples of {  Proeprty_Type_UUID, Package() }
 *      ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), //Std. Property UUID
 *      Package() {
 *              Package(2) { "property-name", <property-value> }
 *      },
 *
 *      ToUUID("ab02a46b-74c7-45a2-bd68-f7d344ef2153"), // ACPI Graph UUID
 *      Package() {
 *        0,            // Revision
 *        1,            // NumberOfGraphs.
 *        Package() {   // Graph[0] Package
 *           1,         // GraphID
 *           // Coresight Graph UUID
 *           ToUUID("3ecbc8b6-1d0e-4fb3-8107-e627f805c6cd"),
 *           3,         // NumberOfLinks aka ports
 *           // Link[0]: Output_0 -> Replicator:Input_0
 *           Package () { 0, 0, \_SB_.RPL0, 1 },
 *           // Link[1]: Input_0 <- Cluster0_Funnel0:Output_0
 *           Package () { 0, 0, \_SB_.CLU0.FUN0, 0 },
 *           // Link[2]: Input_1 <- Cluster1_Funnel0:Output_0
 *            Package () { 1, 0, \_SB_.CLU1.FUN0, 0 },
 *        }     // End of Graph[0] Package
 *
 *      }, // End of ACPI Graph Property
 *  })
 */
static inline bool acpi_validate_dsd_graph(const union acpi_object *graph)
{
        int i, n;
        const union acpi_object *rev, *nr_graphs;

        /* The graph must contain at least the Revision and Number of Graphs */
        if (graph->package.count < 2)
                return false;

        rev = &graph->package.elements[0];
        nr_graphs = &graph->package.elements[1];

        if (rev->type != ACPI_TYPE_INTEGER ||
            nr_graphs->type != ACPI_TYPE_INTEGER)
                return false;

        /* We only support revision 0 */
        if (rev->integer.value != 0)
                return false;

        n = nr_graphs->integer.value;
        /* CoreSight devices are only part of a single Graph */
        if (n != 1)
                return false;

        /* Make sure the ACPI graph package has right number of elements */
        if (graph->package.count != (n + 2))
                return false;

        /*
         * Each entry must be a graph package with at least 3 members :
         * { GraphID, UUID, NumberOfLinks(n), Links[.],... }
         */
        for (i = 2; i < n + 2; i++) {
                const union acpi_object *obj = &graph->package.elements[i];

                if (obj->type != ACPI_TYPE_PACKAGE ||
                    obj->package.count < 3)
                        return false;
        }

        return true;
}

/* acpi_get_dsd_graph   - Find the _DSD Graph property for the given device. */
static const union acpi_object *
acpi_get_dsd_graph(struct acpi_device *adev, struct acpi_buffer *buf)
{
        int i;
        acpi_status status;
        const union acpi_object *dsd;

        status = acpi_evaluate_object_typed(adev->handle, "_DSD", NULL,
                                            buf, ACPI_TYPE_PACKAGE);
        if (ACPI_FAILURE(status))
                return NULL;

        dsd = buf->pointer;

        /*
         * _DSD property consists tuples { Prop_UUID, Package() }
         * Iterate through all the packages and find the Graph.
         */
        for (i = 0; i + 1 < dsd->package.count; i += 2) {
                const union acpi_object *guid, *package;

                guid = &dsd->package.elements[i];
                package = &dsd->package.elements[i + 1];

                /* All _DSD elements must have a UUID and a Package */
                if (!is_acpi_guid(guid) || package->type != ACPI_TYPE_PACKAGE)
                        break;
                /* Skip the non-Graph _DSD packages */
                if (!is_acpi_dsd_graph_guid(guid))
                        continue;
                if (acpi_validate_dsd_graph(package))
                        return package;
                /* Invalid graph format, continue */
                dev_warn(&adev->dev, "Invalid Graph _DSD property\n");
        }

        return NULL;
}

static inline bool
acpi_validate_coresight_graph(const union acpi_object *cs_graph)
{
        int nlinks;

        nlinks = cs_graph->package.elements[2].integer.value;
        /*
         * Graph must have the following fields :
         * { GraphID, GraphUUID, NumberOfLinks, Links... }
         */
        if (cs_graph->package.count != (nlinks + 3))
                return false;
        /* The links are validated in acpi_coresight_parse_link() */
        return true;
}

/*
 * acpi_get_coresight_graph     - Parse the device _DSD tables and find
 * the Graph property matching the CoreSight Graphs.
 *
 * Returns the pointer to the CoreSight Graph Package when found. Otherwise
 * returns NULL.
 */
static const union acpi_object *
acpi_get_coresight_graph(struct acpi_device *adev, struct acpi_buffer *buf)
{
        const union acpi_object *graph_list, *graph;
        int i, nr_graphs;

        graph_list = acpi_get_dsd_graph(adev, buf);
        if (!graph_list)
                return graph_list;

        nr_graphs = graph_list->package.elements[1].integer.value;

        for (i = 2; i < nr_graphs + 2; i++) {
                graph = &graph_list->package.elements[i];
                if (!is_acpi_coresight_graph(graph))
                        continue;
                if (acpi_validate_coresight_graph(graph))
                        return graph;
                /* Invalid graph format */
                break;
        }

        return NULL;
}

/*
 * acpi_coresight_parse_link    - Parse the given Graph connection
 * of the device and populate the coresight_connection for an output
 * connection.
 *
 * CoreSight Graph specification mandates that the direction of the data
 * flow must be specified in the link. i.e,
 *
 *      SourcePortAddress,      // Integer
 *      DestinationPortAddress, // Integer
 *      DestinationDeviceName,  // Reference to another device
 *      DirectionOfFlow,        // 1 for output(master), 0 for input(slave)
 *
 * Returns the direction of the data flow [ Input(slave) or Output(master) ]
 * upon success.
 * Returns an negative error number otherwise.
 */
static int acpi_coresight_parse_link(struct acpi_device *adev,
                                     const union acpi_object *link,
                                     struct coresight_connection *conn)
{
        int dir;
        const union acpi_object *fields;
        struct acpi_device *r_adev;
        struct device *rdev;

        if (link->type != ACPI_TYPE_PACKAGE ||
            link->package.count != 4)
                return -EINVAL;

        fields = link->package.elements;

        if (fields[0].type != ACPI_TYPE_INTEGER ||
            fields[1].type != ACPI_TYPE_INTEGER ||
            fields[2].type != ACPI_TYPE_LOCAL_REFERENCE ||
            fields[3].type != ACPI_TYPE_INTEGER)
                return -EINVAL;

        r_adev = acpi_fetch_acpi_dev(fields[2].reference.handle);
        if (!r_adev)
                return -ENODEV;

        dir = fields[3].integer.value;
        if (dir == ACPI_CORESIGHT_LINK_MASTER) {
                conn->src_port = fields[0].integer.value;
                conn->dest_port = fields[1].integer.value;
                rdev = coresight_find_device_by_fwnode(&r_adev->fwnode);
                if (!rdev)
                        return -EPROBE_DEFER;
                /*
                 * Hold the refcount to the target device. This could be
                 * released via:
                 * 1) coresight_release_platform_data() if the probe fails or
                 *    this device is unregistered.
                 * 2) While removing the target device via
                 *    coresight_remove_match().
                 */
                conn->dest_fwnode = fwnode_handle_get(&r_adev->fwnode);
        } else if (dir == ACPI_CORESIGHT_LINK_SLAVE) {
                /*
                 * We are only interested in the port number
                 * for the input ports at this component.
                 * Store the port number in child_port.
                 */
                conn->dest_port = fields[0].integer.value;
        } else {
                /* Invalid direction */
                return -EINVAL;
        }

        return dir;
}

/*
 * acpi_coresight_parse_graph   - Parse the _DSD CoreSight graph
 * connection information and populate the supplied coresight_platform_data
 * instance.
 */
static int acpi_coresight_parse_graph(struct device *dev,
                                      struct acpi_device *adev,
                                      struct coresight_platform_data *pdata)
{
        int ret = 0;
        int i, nlinks;
        const union acpi_object *graph;
        struct coresight_connection conn, zero_conn = {};
        struct coresight_connection *new_conn;
        struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };

        graph = acpi_get_coresight_graph(adev, &buf);
        /*
         * There are no graph connections, which is fine for some components.
         * e.g., ETE
         */
        if (!graph)
                goto free;

        nlinks = graph->package.elements[2].integer.value;
        if (!nlinks)
                goto free;

        for (i = 0; i < nlinks; i++) {
                const union acpi_object *link = &graph->package.elements[3 + i];
                int dir;

                conn = zero_conn;
                dir = acpi_coresight_parse_link(adev, link, &conn);
                if (dir < 0) {
                        ret = dir;
                        goto free;
                }

                if (dir == ACPI_CORESIGHT_LINK_MASTER) {
                        new_conn = coresight_add_out_conn(dev, pdata, &conn);
                        if (IS_ERR(new_conn)) {
                                ret = PTR_ERR(new_conn);
                                goto free;
                        }
                }
        }

free:
        /*
         * When ACPI fails to alloc a buffer, it will free the buffer
         * created via ACPI_ALLOCATE_BUFFER and set to NULL.
         * ACPI_FREE can handle NULL pointers, so free it directly.
         */
        ACPI_FREE(buf.pointer);
        return ret;
}

/*
 * acpi_handle_to_logical_cpuid - Map a given acpi_handle to the
 * logical CPU id of the corresponding CPU device.
 *
 * Returns the logical CPU id when found. Otherwise returns >= nr_cpus_id.
 */
static int
acpi_handle_to_logical_cpuid(acpi_handle handle)
{
        int i;
        struct acpi_processor *pr;

        for_each_possible_cpu(i) {
                pr = per_cpu(processors, i);
                if (pr && pr->handle == handle)
                        break;
        }

        return i;
}

/*
 * acpi_coresigh_get_cpu - Find the logical CPU id of the CPU associated
 * with this coresight device. With ACPI bindings, the CoreSight components
 * are listed as child device of the associated CPU.
 *
 * Returns the logical CPU id when found. Otherwise returns 0.
 */
static int acpi_coresight_get_cpu(struct device *dev)
{
        int cpu;
        acpi_handle cpu_handle;
        acpi_status status;
        struct acpi_device *adev = ACPI_COMPANION(dev);

        if (!adev)
                return -ENODEV;
        status = acpi_get_parent(adev->handle, &cpu_handle);
        if (ACPI_FAILURE(status))
                return -ENODEV;

        cpu = acpi_handle_to_logical_cpuid(cpu_handle);
        if (cpu >= nr_cpu_ids)
                return -ENODEV;
        return cpu;
}

static int
acpi_get_coresight_platform_data(struct device *dev,
                                 struct coresight_platform_data *pdata)
{
        struct acpi_device *adev;

        adev = ACPI_COMPANION(dev);
        if (!adev)
                return -EINVAL;

        return acpi_coresight_parse_graph(dev, adev, pdata);
}

#else

static inline int
acpi_get_coresight_platform_data(struct device *dev,
                                 struct coresight_platform_data *pdata)
{
        return -ENOENT;
}

static inline int acpi_coresight_get_cpu(struct device *dev)
{
        return -ENODEV;
}
#endif

int coresight_get_cpu(struct device *dev)
{
        if (is_of_node(dev->fwnode))
                return of_coresight_get_cpu(dev);
        else if (is_acpi_device_node(dev->fwnode))
                return acpi_coresight_get_cpu(dev);
        return 0;
}
EXPORT_SYMBOL_GPL(coresight_get_cpu);

struct coresight_platform_data *
coresight_get_platform_data(struct device *dev)
{
        int ret = -ENOENT;
        struct coresight_platform_data *pdata = NULL;
        struct fwnode_handle *fwnode = dev_fwnode(dev);

        if (IS_ERR_OR_NULL(fwnode))
                goto error;

        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata) {
                ret = -ENOMEM;
                goto error;
        }

        if (is_of_node(fwnode))
                ret = of_get_coresight_platform_data(dev, pdata);
        else if (is_acpi_device_node(fwnode))
                ret = acpi_get_coresight_platform_data(dev, pdata);

        if (!ret)
                return pdata;
error:
        if (!IS_ERR_OR_NULL(pdata))
                /* Cleanup the connection information */
                coresight_release_platform_data(NULL, dev, pdata);
        return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(coresight_get_platform_data);