drivers/hwtracing/coresight/of_coresight.c - kernel/common - Git at Google

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

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

 static void of_coresight_get_ports_legacy(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_coresight_legacy_ep_is_input(ep))
 			in++;
 		else
 			out++;

 	} while (ep);

 	*nr_inport = in;
 	*nr_outport = out;
 }

 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_input_ports_node(const struct device_node *node)
 {
 	return of_get_child_by_name(node, "in-ports");
 }

 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 inline int
 of_coresight_count_ports(struct device_node *port_parent)
 {
 	int i = 0;
 	struct device_node *ep = NULL;

 	while ((ep = of_graph_get_next_endpoint(port_parent, ep)))
 		i++;
 	return i;
 }

 static void of_coresight_get_ports(const struct device_node *node,
 				   int *nr_inport, int *nr_outport)
 {
 	struct device_node *input_ports = NULL, *output_ports = NULL;

 	input_ports = of_coresight_get_input_ports_node(node);
 	output_ports = of_coresight_get_output_ports_node(node);

 	if (input_ports || output_ports) {
 		if (input_ports) {
 			*nr_inport = of_coresight_count_ports(input_ports);
 			of_node_put(input_ports);
 		}
 		if (output_ports) {
 			*nr_outport = of_coresight_count_ports(output_ports);
 			of_node_put(output_ports);
 		}
 	} else {
 		/* Fall back to legacy DT bindings parsing */
 		of_coresight_get_ports_legacy(node, nr_inport, nr_outport);
 	}
 }

 static int of_coresight_alloc_memory(struct device *dev,
 			struct coresight_platform_data *pdata)
 {
 	if (pdata->nr_outport) {
 		pdata->conns = devm_kzalloc(dev, pdata->nr_outport *
 					    sizeof(*pdata->conns),
 					    GFP_KERNEL);
 		if (!pdata->conns)
 			return -ENOMEM;
 	}

 	return 0;
 }

 int of_coresight_get_cpu(const struct device_node *node)
 {
 	int cpu;
 	struct device_node *dn;

 	dn = of_parse_phandle(node, "cpu", 0);
 	/* Affinity defaults to CPU0 */
 	if (!dn)
 		return 0;
 	cpu = of_cpu_node_to_id(dn);
 	of_node_put(dn);

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

 /*
  * of_coresight_parse_endpoint : Parse the given output endpoint @ep
  * and fill the connection information in @conn
  *
  * Parses the local port, remote device name and the remote port.
  *
  * Returns :
  *	 1	- If the parsing is successful and a connection record
  *		  was created for an output connection.
  *	 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_connection *conn)
 {
 	int ret = 0;
 	struct of_endpoint endpoint, rendpoint;
 	struct device_node *rparent = NULL;
 	struct device_node *rep = NULL;
 	struct device *rdev = NULL;

 	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;

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

 		conn->outport = endpoint.port;
 		conn->child_name = devm_kstrdup(dev,
 						dev_name(rdev),
 						GFP_KERNEL);
 		conn->child_port = rendpoint.port;
 		/* Connection record updated */
 		ret = 1;
 	} while (0);

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

 	return ret;
 }

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

 	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);
 	pdata->cpu = of_coresight_get_cpu(node);

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

 	/* If there are no output connections, we are done */
 	if (!pdata->nr_outport)
 		return pdata;

 	ret = of_coresight_alloc_memory(dev, pdata);
 	if (ret)
 		return ERR_PTR(ret);

 	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) {
 		legacy_binding = true;
 		parent = node;
 		dev_warn_once(dev, "Uses obsolete Coresight DT bindings\n");
 	}

 	conn = pdata->conns;

 	/* Iterate through each output port to discover topology */
 	while ((ep = of_graph_get_next_endpoint(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, conn);
 		switch (ret) {
 		case 1:
 			conn++;		/* Fall through */
 		case 0:
 			break;
 		default:
 			return ERR_PTR(ret);
 		}
 	}

 	return pdata;
 }
 EXPORT_SYMBOL_GPL(of_get_coresight_platform_data);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (c) 2012, The Linux Foundation. All rights reserved.
	*/

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

	static void of_coresight_get_ports_legacy(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_coresight_legacy_ep_is_input(ep))
	in++;
	else
	out++;

	} while (ep);

	*nr_inport = in;
	*nr_outport = out;
	}

	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_input_ports_node(const struct device_node *node)
	{
	return of_get_child_by_name(node, "in-ports");
	}

	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 inline int
	of_coresight_count_ports(struct device_node *port_parent)
	{
	int i = 0;
	struct device_node *ep = NULL;

	while ((ep = of_graph_get_next_endpoint(port_parent, ep)))
	i++;
	return i;
	}

	static void of_coresight_get_ports(const struct device_node *node,
	int nr_inport, int nr_outport)
	{
	struct device_node input_ports = NULL, output_ports = NULL;

	input_ports = of_coresight_get_input_ports_node(node);
	output_ports = of_coresight_get_output_ports_node(node);

	if (input_ports \|\| output_ports) {
	if (input_ports) {
	*nr_inport = of_coresight_count_ports(input_ports);
	of_node_put(input_ports);
	}
	if (output_ports) {
	*nr_outport = of_coresight_count_ports(output_ports);
	of_node_put(output_ports);
	}
	} else {
	/* Fall back to legacy DT bindings parsing */
	of_coresight_get_ports_legacy(node, nr_inport, nr_outport);
	}
	}

	static int of_coresight_alloc_memory(struct device *dev,
	struct coresight_platform_data *pdata)
	{
	if (pdata->nr_outport) {
	pdata->conns = devm_kzalloc(dev, pdata->nr_outport *
	sizeof(*pdata->conns),
	GFP_KERNEL);
	if (!pdata->conns)
	return -ENOMEM;
	}

	return 0;
	}

	int of_coresight_get_cpu(const struct device_node *node)
	{
	int cpu;
	struct device_node *dn;

	dn = of_parse_phandle(node, "cpu", 0);
	/* Affinity defaults to CPU0 */
	if (!dn)
	return 0;
	cpu = of_cpu_node_to_id(dn);
	of_node_put(dn);

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

	/*
	* of_coresight_parse_endpoint : Parse the given output endpoint @ep
	* and fill the connection information in @conn
	*
	* Parses the local port, remote device name and the remote port.
	*
	* Returns :
	* 1 - If the parsing is successful and a connection record
	* was created for an output connection.
	* 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_connection *conn)
	{
	int ret = 0;
	struct of_endpoint endpoint, rendpoint;
	struct device_node *rparent = NULL;
	struct device_node *rep = NULL;
	struct device *rdev = NULL;

	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;

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

	conn->outport = endpoint.port;
	conn->child_name = devm_kstrdup(dev,
	dev_name(rdev),
	GFP_KERNEL);
	conn->child_port = rendpoint.port;
	/* Connection record updated */
	ret = 1;
	} while (0);

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

	return ret;
	}

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

	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);
	pdata->cpu = of_coresight_get_cpu(node);

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

	/* If there are no output connections, we are done */
	if (!pdata->nr_outport)
	return pdata;

	ret = of_coresight_alloc_memory(dev, pdata);
	if (ret)
	return ERR_PTR(ret);

	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) {
	legacy_binding = true;
	parent = node;
	dev_warn_once(dev, "Uses obsolete Coresight DT bindings\n");
	}

	conn = pdata->conns;

	/* Iterate through each output port to discover topology */
	while ((ep = of_graph_get_next_endpoint(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, conn);
	switch (ret) {
	case 1:
	conn++; /* Fall through */
	case 0:
	break;
	default:
	return ERR_PTR(ret);
	}
	}

	return pdata;
	}
	EXPORT_SYMBOL_GPL(of_get_coresight_platform_data);