linux_kernel/drivers/hwtracing/coresight/of_coresight.c

/* 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);