linux/drivers/hwtracing/coresight/coresight-cti-platform.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2019, The Linaro Limited. All rights reserved.
 */

#include <dt-bindings/arm/coresight-cti-dt.h>
#include <linux/of.h>

#include "coresight-cti.h"

/* Number of CTI signals in the v8 architecturally defined connection */
#define NR_V8PE_IN_SIGS		2
#define NR_V8PE_OUT_SIGS	3
#define NR_V8ETM_INOUT_SIGS	4

/* CTI device tree connection property keywords */
#define CTI_DT_V8ARCH_COMPAT	"arm,coresight-cti-v8-arch"
#define CTI_DT_CSDEV_ASSOC	"arm,cs-dev-assoc"

#ifdef CONFIG_OF
/*
 * CTI can be bound to a CPU, or a system device.
 * CPU can be declared at the device top level or in a connections node
 * so need to check relative to node not device.
 */
static int of_cti_get_cpu_at_node(const struct device_node *node)
{
	int cpu;
	struct device_node *dn;

	if (node == NULL)
		return -1;

	dn = of_parse_phandle(node, "cpu", 0);
	/* CTI affinity defaults to no cpu */
	if (!dn)
		return -1;
	cpu = of_cpu_node_to_id(dn);
	of_node_put(dn);

	/* No Affinity  if no cpu nodes are found */
	return (cpu < 0) ? -1 : cpu;
}

#else
static int of_cti_get_cpu_at_node(const struct device_node *node)
{
	return -1;
}

#endif

/*
 * CTI can be bound to a CPU, or a system device.
 * CPU can be declared at the device top level or in a connections node
 * so need to check relative to node not device.
 */
static int cti_plat_get_cpu_at_node(struct fwnode_handle *fwnode)
{
	if (is_of_node(fwnode))
		return of_cti_get_cpu_at_node(to_of_node(fwnode));
	return -1;
}

const char *cti_plat_get_node_name(struct fwnode_handle *fwnode)
{
	if (is_of_node(fwnode))
		return of_node_full_name(to_of_node(fwnode));
	return "unknown";
}

/*
 * Extract a name from the fwnode.
 * If the device associated with the node is a coresight_device, then return
 * that name and the coresight_device pointer, otherwise return the node name.
 */
static const char *
cti_plat_get_csdev_or_node_name(struct fwnode_handle *fwnode,
				struct coresight_device **csdev)
{
	const char *name = NULL;
	*csdev = coresight_find_csdev_by_fwnode(fwnode);
	if (*csdev)
		name = dev_name(&(*csdev)->dev);
	else
		name = cti_plat_get_node_name(fwnode);
	return name;
}

static int cti_plat_create_v8_etm_connection(struct device *dev,
					     struct cti_drvdata *drvdata)
{
	int ret = -ENOMEM, i;
	struct fwnode_handle *root_fwnode, *cs_fwnode;
	const char *assoc_name = NULL;
	struct coresight_device *csdev;
	struct cti_trig_con *tc = NULL;

	root_fwnode = dev_fwnode(dev);
	if (IS_ERR_OR_NULL(root_fwnode))
		return -EINVAL;

	/* Can optionally have an etm node - return if not  */
	cs_fwnode = fwnode_find_reference(root_fwnode, CTI_DT_CSDEV_ASSOC, 0);
	if (IS_ERR_OR_NULL(cs_fwnode))
		return 0;

	/* allocate memory */
	tc = cti_allocate_trig_con(dev, NR_V8ETM_INOUT_SIGS,
				   NR_V8ETM_INOUT_SIGS);
	if (!tc)
		goto create_v8_etm_out;

	/* build connection data */
	tc->con_in->used_mask = 0xF0; /* sigs <4,5,6,7> */
	tc->con_out->used_mask = 0xF0; /* sigs <4,5,6,7> */

	/*
	 * The EXTOUT type signals from the ETM are connected to a set of input
	 * triggers on the CTI, the EXTIN being connected to output triggers.
	 */
	for (i = 0; i < NR_V8ETM_INOUT_SIGS; i++) {
		tc->con_in->sig_types[i] = ETM_EXTOUT;
		tc->con_out->sig_types[i] = ETM_EXTIN;
	}

	/*
	 * We look to see if the ETM coresight device associated with this
	 * handle has been registered with the system - i.e. probed before
	 * this CTI. If so csdev will be non NULL and we can use the device
	 * name and pass the csdev to the connection entry function where
	 * the association will be recorded.
	 * If not, then simply record the name in the connection data, the
	 * probing of the ETM will call into the CTI driver API to update the
	 * association then.
	 */
	assoc_name = cti_plat_get_csdev_or_node_name(cs_fwnode, &csdev);
	ret = cti_add_connection_entry(dev, drvdata, tc, csdev, assoc_name);

create_v8_etm_out:
	fwnode_handle_put(cs_fwnode);
	return ret;
}

/*
 * Create an architecturally defined v8 connection
 * must have a cpu, can have an ETM.
 */
static int cti_plat_create_v8_connections(struct device *dev,
					  struct cti_drvdata *drvdata)
{
	struct cti_device *cti_dev = &drvdata->ctidev;
	struct cti_trig_con *tc = NULL;
	int cpuid = 0;
	char cpu_name_str[16];
	int ret = -ENOMEM;

	/* Must have a cpu node */
	cpuid = cti_plat_get_cpu_at_node(dev_fwnode(dev));
	if (cpuid < 0) {
		dev_warn(dev,
			 "ARM v8 architectural CTI connection: missing cpu\n");
		return -EINVAL;
	}
	cti_dev->cpu = cpuid;

	/* Allocate the v8 cpu connection memory */
	tc = cti_allocate_trig_con(dev, NR_V8PE_IN_SIGS, NR_V8PE_OUT_SIGS);
	if (!tc)
		goto of_create_v8_out;

	/* Set the v8 PE CTI connection data */
	tc->con_in->used_mask = 0x3; /* sigs <0 1> */
	tc->con_in->sig_types[0] = PE_DBGTRIGGER;
	tc->con_in->sig_types[1] = PE_PMUIRQ;
	tc->con_out->used_mask = 0x7; /* sigs <0 1 2 > */
	tc->con_out->sig_types[0] = PE_EDBGREQ;
	tc->con_out->sig_types[1] = PE_DBGRESTART;
	tc->con_out->sig_types[2] = PE_CTIIRQ;
	scnprintf(cpu_name_str, sizeof(cpu_name_str), "cpu%d", cpuid);

	ret = cti_add_connection_entry(dev, drvdata, tc, NULL, cpu_name_str);
	if (ret)
		goto of_create_v8_out;

	/* Create the v8 ETM associated connection */
	ret = cti_plat_create_v8_etm_connection(dev, drvdata);
	if (ret)
		goto of_create_v8_out;

	/* filter pe_edbgreq - PE trigout sig <0> */
	drvdata->config.trig_out_filter |= 0x1;

of_create_v8_out:
	return ret;
}

static int cti_plat_check_v8_arch_compatible(struct device *dev)
{
	struct fwnode_handle *fwnode = dev_fwnode(dev);

	if (is_of_node(fwnode))
		return of_device_is_compatible(to_of_node(fwnode),
					       CTI_DT_V8ARCH_COMPAT);
	return 0;
}

/* get the hardware configuration & connection data. */
int cti_plat_get_hw_data(struct device *dev,
			 struct cti_drvdata *drvdata)
{
	int rc = 0;
	struct cti_device *cti_dev = &drvdata->ctidev;

	/* check for a v8 architectural CTI device */
	if (cti_plat_check_v8_arch_compatible(dev)) {
		rc = cti_plat_create_v8_connections(dev, drvdata);
		if (rc)
			return rc;
	}

	/* if no connections, just add a single default based on max IN-OUT */
	if (cti_dev->nr_trig_con == 0)
		rc = cti_add_default_connection(dev, drvdata);
	return rc;
}

struct coresight_platform_data *
coresight_cti_get_platform_data(struct device *dev)
{
	int ret = -ENOENT;
	struct coresight_platform_data *pdata = NULL;
	struct fwnode_handle *fwnode = dev_fwnode(dev);
	struct cti_drvdata *drvdata = dev_get_drvdata(dev);

	if (IS_ERR_OR_NULL(fwnode))
		goto error;

	/*
	 * Alloc platform data but leave it zero init. CTI does not use the
	 * same connection infrastructuree as trace path components but an
	 * empty struct enables us to use the standard coresight component
	 * registration code.
	 */
	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata) {
		ret = -ENOMEM;
		goto error;
	}

	/* get some CTI specifics */
	ret = cti_plat_get_hw_data(dev, drvdata);

	if (!ret)
		return pdata;
error:
	return ERR_PTR(ret);
}