/* Copyright (c) 2012, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

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


static int of_dev_node_match(struct device *dev, void *data)
{
        return dev->of_node == data;
}

static struct device *
of_coresight_get_endpoint_device(struct device_node *endpoint)
{
        struct device *dev = NULL;

        /*
         * If we have a non-configurable replicator, it will be found on the
         * platform bus.
         */
        dev = bus_find_device(&platform_bus_type, NULL,
                              endpoint, of_dev_node_match);
        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(&amba_bustype, NULL,
                               endpoint, of_dev_node_match);
}

static void of_coresight_get_ports(const struct device_node *node,
                                   int *nr_inport, int *nr_outport)
{
        struct device_node *ep = NULL;
        int in = 0, out = 0;

        do {
                ep = of_graph_get_next_endpoint(node, ep);
                if (!ep)
                        break;

                if (of_property_read_bool(ep, "slave-mode"))
                        in++;
                else
                        out++;

        } while (ep);

        *nr_inport = in;
        *nr_outport = out;
}

static int of_coresight_alloc_memory(struct device *dev,
                        struct coresight_platform_data *pdata)
{
        /* List of output port on this component */
        pdata->outports = devm_kzalloc(dev, pdata->nr_outport *
                                       sizeof(*pdata->outports),
                                       GFP_KERNEL);
        if (!pdata->outports)
                return -ENOMEM;

        /* Children connected to this component via @outports */
        pdata->child_names = devm_kzalloc(dev, pdata->nr_outport *
                                          sizeof(*pdata->child_names),
                                          GFP_KERNEL);
        if (!pdata->child_names)
                return -ENOMEM;

        /* Port number on the child this component is connected to */
        pdata->child_ports = devm_kzalloc(dev, pdata->nr_outport *
                                          sizeof(*pdata->child_ports),
                                          GFP_KERNEL);
        if (!pdata->child_ports)
                return -ENOMEM;

        return 0;
}

int of_coresight_get_cpu(const struct device_node *node)
{
        int cpu;
        bool found;
        struct device_node *dn, *np;

        dn = of_parse_phandle(node, "cpu", 0);

        /* Affinity defaults to CPU0 */
        if (!dn)
                return 0;

        for_each_possible_cpu(cpu) {
                np = of_cpu_device_node_get(cpu);
                found = (dn == np);
                of_node_put(np);
                if (found)
                        break;
        }
        of_node_put(dn);

        /* Affinity to CPU0 if no cpu nodes are found */
        return found ? cpu : 0;
}
EXPORT_SYMBOL_GPL(of_coresight_get_cpu);

struct coresight_platform_data *
of_get_coresight_platform_data(struct device *dev,
                               const struct device_node *node)
{
        int i = 0, ret = 0;
        struct coresight_platform_data *pdata;
        struct of_endpoint endpoint, rendpoint;
        struct device *rdev;
        struct device_node *ep = NULL;
        struct device_node *rparent = NULL;
        struct device_node *rport = NULL;

        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return ERR_PTR(-ENOMEM);

        /* Use device name as sysfs handle */
        pdata->name = dev_name(dev);

        /* Get the number of input and output port for this component */
        of_coresight_get_ports(node, &pdata->nr_inport, &pdata->nr_outport);

        if (pdata->nr_outport) {
                ret = of_coresight_alloc_memory(dev, pdata);
                if (ret)
                        return ERR_PTR(ret);

                /* Iterate through each port to discover topology */
                do {
                        /* Get a handle on a port */
                        ep = of_graph_get_next_endpoint(node, ep);
                        if (!ep)
                                break;

                        /*
                         * No need to deal with input ports, processing for as
                         * processing for output ports will deal with them.
                         */
                        if (of_find_property(ep, "slave-mode", NULL))
                                continue;

                        /* Get a handle on the local endpoint */
                        ret = of_graph_parse_endpoint(ep, &endpoint);

                        if (ret)
                                continue;

                        /* The local out port number */
                        pdata->outports[i] = endpoint.port;

                        /*
                         * Get a handle on the remote port and parent
                         * attached to it.
                         */
                        rparent = of_graph_get_remote_port_parent(ep);
                        rport = of_graph_get_remote_port(ep);

                        if (!rparent || !rport)
                                continue;

                        if (of_graph_parse_endpoint(rport, &rendpoint))
                                continue;

                        rdev = of_coresight_get_endpoint_device(rparent);
                        if (!rdev)
                                return ERR_PTR(-EPROBE_DEFER);

                        pdata->child_names[i] = dev_name(rdev);
                        pdata->child_ports[i] = rendpoint.id;

                        i++;
                } while (ep);
        }

        pdata->cpu = of_coresight_get_cpu(node);

        return pdata;
}
EXPORT_SYMBOL_GPL(of_get_coresight_platform_data);