// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2019, The Linaro Limited. All rights reserved.
 */
#include <linux/coresight.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/property.h>
#include <linux/slab.h>

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

#include "coresight-cti.h"
#include "coresight-priv.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 trigger connection node keyword */
#define CTI_DT_CONNS            "trig-conns"

/* 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"
#define CTI_DT_TRIGIN_SIGS      "arm,trig-in-sigs"
#define CTI_DT_TRIGOUT_SIGS     "arm,trig-out-sigs"
#define CTI_DT_TRIGIN_TYPES     "arm,trig-in-types"
#define CTI_DT_TRIGOUT_TYPES    "arm,trig-out-types"
#define CTI_DT_FILTER_OUT_SIGS  "arm,trig-filters"
#define CTI_DT_CONN_NAME        "arm,trig-conn-name"
#define CTI_DT_CTM_ID           "arm,cti-ctm-id"

#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 bool cti_plat_node_name_eq(struct fwnode_handle *fwnode,
                                  const char *name)
{
        if (is_of_node(fwnode))
                return of_node_name_eq(to_of_node(fwnode), name);
        return false;
}

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(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;
}

static int cti_plat_count_sig_elements(const struct fwnode_handle *fwnode,
                                       const char *name)
{
        int nr_elem = fwnode_property_count_u32(fwnode, name);

        return (nr_elem < 0 ? 0 : nr_elem);
}

static int cti_plat_read_trig_group(struct cti_trig_grp *tgrp,
                                    const struct fwnode_handle *fwnode,
                                    const char *grp_name)
{
        int idx, err = 0;
        u32 *values;

        if (!tgrp->nr_sigs)
                return 0;

        values = kcalloc(tgrp->nr_sigs, sizeof(u32), GFP_KERNEL);
        if (!values)
                return -ENOMEM;

        err = fwnode_property_read_u32_array(fwnode, grp_name,
                                             values, tgrp->nr_sigs);

        if (!err) {
                /* set the signal usage mask */
                for (idx = 0; idx < tgrp->nr_sigs; idx++)
                        tgrp->used_mask |= BIT(values[idx]);
        }

        kfree(values);
        return err;
}

static int cti_plat_read_trig_types(struct cti_trig_grp *tgrp,
                                    const struct fwnode_handle *fwnode,
                                    const char *type_name)
{
        int items, err = 0, nr_sigs;
        u32 *values = NULL, i;

        /* allocate an array according to number of signals in connection */
        nr_sigs = tgrp->nr_sigs;
        if (!nr_sigs)
                return 0;

        /* see if any types have been included in the device description */
        items = cti_plat_count_sig_elements(fwnode, type_name);
        if (items > nr_sigs)
                return -EINVAL;

        /* need an array to store the values iff there are any */
        if (items) {
                values = kcalloc(items, sizeof(u32), GFP_KERNEL);
                if (!values)
                        return -ENOMEM;

                err = fwnode_property_read_u32_array(fwnode, type_name,
                                                     values, items);
                if (err)
                        goto read_trig_types_out;
        }

        /*
         * Match type id to signal index, 1st type to 1st index etc.
         * If fewer types than signals default remainder to GEN_IO.
         */
        for (i = 0; i < nr_sigs; i++) {
                if (i < items) {
                        tgrp->sig_types[i] =
                                values[i] < CTI_TRIG_MAX ? values[i] : GEN_IO;
                } else {
                        tgrp->sig_types[i] = GEN_IO;
                }
        }

read_trig_types_out:
        kfree(values);
        return err;
}

static int cti_plat_process_filter_sigs(struct cti_drvdata *drvdata,
                                        const struct fwnode_handle *fwnode)
{
        struct cti_trig_grp *tg = NULL;
        int err = 0, nr_filter_sigs;

        nr_filter_sigs = cti_plat_count_sig_elements(fwnode,
                                                     CTI_DT_FILTER_OUT_SIGS);
        if (nr_filter_sigs == 0)
                return 0;

        if (nr_filter_sigs > drvdata->config.nr_trig_max)
                return -EINVAL;

        tg = kzalloc(sizeof(*tg), GFP_KERNEL);
        if (!tg)
                return -ENOMEM;

        err = cti_plat_read_trig_group(tg, fwnode, CTI_DT_FILTER_OUT_SIGS);
        if (!err)
                drvdata->config.trig_out_filter |= tg->used_mask;

        kfree(tg);
        return err;
}

static int cti_plat_create_connection(struct device *dev,
                                      struct cti_drvdata *drvdata,
                                      struct fwnode_handle *fwnode)
{
        struct cti_trig_con *tc = NULL;
        int cpuid = -1, err = 0;
        struct fwnode_handle *cs_fwnode = NULL;
        struct coresight_device *csdev = NULL;
        const char *assoc_name = "unknown";
        char cpu_name_str[16];
        int nr_sigs_in, nr_sigs_out;

        /* look to see how many in and out signals we have */
        nr_sigs_in = cti_plat_count_sig_elements(fwnode, CTI_DT_TRIGIN_SIGS);
        nr_sigs_out = cti_plat_count_sig_elements(fwnode, CTI_DT_TRIGOUT_SIGS);

        if ((nr_sigs_in > drvdata->config.nr_trig_max) ||
            (nr_sigs_out > drvdata->config.nr_trig_max))
                return -EINVAL;

        tc = cti_allocate_trig_con(dev, nr_sigs_in, nr_sigs_out);
        if (!tc)
                return -ENOMEM;

        /* look for the signals properties. */
        err = cti_plat_read_trig_group(tc->con_in, fwnode,
                                       CTI_DT_TRIGIN_SIGS);
        if (err)
                goto create_con_err;

        err = cti_plat_read_trig_types(tc->con_in, fwnode,
                                       CTI_DT_TRIGIN_TYPES);
        if (err)
                goto create_con_err;

        err = cti_plat_read_trig_group(tc->con_out, fwnode,
                                       CTI_DT_TRIGOUT_SIGS);
        if (err)
                goto create_con_err;

        err = cti_plat_read_trig_types(tc->con_out, fwnode,
                                       CTI_DT_TRIGOUT_TYPES);
        if (err)
                goto create_con_err;

        err = cti_plat_process_filter_sigs(drvdata, fwnode);
        if (err)
                goto create_con_err;

        /* read the connection name if set - may be overridden by later */
        fwnode_property_read_string(fwnode, CTI_DT_CONN_NAME, &assoc_name);

        /* associated cpu ? */
        cpuid = cti_plat_get_cpu_at_node(fwnode);
        if (cpuid >= 0) {
                drvdata->ctidev.cpu = cpuid;
                scnprintf(cpu_name_str, sizeof(cpu_name_str), "cpu%d", cpuid);
                assoc_name = cpu_name_str;
        } else {
                /* associated device ? */
                cs_fwnode = fwnode_find_reference(fwnode,
                                                  CTI_DT_CSDEV_ASSOC, 0);
                if (!IS_ERR(cs_fwnode)) {
                        assoc_name = cti_plat_get_csdev_or_node_name(cs_fwnode,
                                                                     &csdev);
                        fwnode_handle_put(cs_fwnode);
                }
        }
        /* set up a connection */
        err = cti_add_connection_entry(dev, drvdata, tc, csdev, assoc_name);

create_con_err:
        return err;
}

static int cti_plat_create_impdef_connections(struct device *dev,
                                              struct cti_drvdata *drvdata)
{
        int rc = 0;
        struct fwnode_handle *fwnode = dev_fwnode(dev);
        struct fwnode_handle *child = NULL;

        if (IS_ERR_OR_NULL(fwnode))
                return -EINVAL;

        fwnode_for_each_child_node(fwnode, child) {
                if (cti_plat_node_name_eq(child, CTI_DT_CONNS))
                        rc = cti_plat_create_connection(dev, drvdata,
                                                        child);
                if (rc != 0)
                        break;
        }
        fwnode_handle_put(child);

        return rc;
}

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

        /* get any CTM ID - defaults to 0 */
        device_property_read_u32(dev, CTI_DT_CTM_ID, &cti_dev->ctm_id);

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