drm/panthor: Don't add write fences to the shared BOs

[drm/drm-misc.git] / drivers / opp / of.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Generic OPP OF helpers
 *
 * Copyright (C) 2009-2010 Texas Instruments Incorporated.
 *      Nishanth Menon
 *      Romit Dasgupta
 *      Kevin Hilman
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/cpu.h>
#include <linux/errno.h>
#include <linux/device.h>
#include <linux/of.h>
#include <linux/pm_domain.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/energy_model.h>

#include "opp.h"

/* OPP tables with uninitialized required OPPs, protected by opp_table_lock */
static LIST_HEAD(lazy_opp_tables);

/*
 * Returns opp descriptor node for a device node, caller must
 * do of_node_put().
 */
static struct device_node *_opp_of_get_opp_desc_node(struct device_node *np,
                                                     int index)
{
        /* "operating-points-v2" can be an array for power domain providers */
        return of_parse_phandle(np, "operating-points-v2", index);
}

/* Returns opp descriptor node for a device, caller must do of_node_put() */
struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev)
{
        return _opp_of_get_opp_desc_node(dev->of_node, 0);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_opp_desc_node);

struct opp_table *_managed_opp(struct device *dev, int index)
{
        struct opp_table *opp_table, *managed_table = NULL;
        struct device_node *np;

        np = _opp_of_get_opp_desc_node(dev->of_node, index);
        if (!np)
                return NULL;

        list_for_each_entry(opp_table, &opp_tables, node) {
                if (opp_table->np == np) {
                        /*
                         * Multiple devices can point to the same OPP table and
                         * so will have same node-pointer, np.
                         *
                         * But the OPPs will be considered as shared only if the
                         * OPP table contains a "opp-shared" property.
                         */
                        if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {
                                _get_opp_table_kref(opp_table);
                                managed_table = opp_table;
                        }

                        break;
                }
        }

        of_node_put(np);

        return managed_table;
}

/* The caller must call dev_pm_opp_put() after the OPP is used */
static struct dev_pm_opp *_find_opp_of_np(struct opp_table *opp_table,
                                          struct device_node *opp_np)
{
        struct dev_pm_opp *opp;

        mutex_lock(&opp_table->lock);

        list_for_each_entry(opp, &opp_table->opp_list, node) {
                if (opp->np == opp_np) {
                        dev_pm_opp_get(opp);
                        mutex_unlock(&opp_table->lock);
                        return opp;
                }
        }

        mutex_unlock(&opp_table->lock);

        return NULL;
}

static struct device_node *of_parse_required_opp(struct device_node *np,
                                                 int index)
{
        return of_parse_phandle(np, "required-opps", index);
}

/* The caller must call dev_pm_opp_put_opp_table() after the table is used */
static struct opp_table *_find_table_of_opp_np(struct device_node *opp_np)
{
        struct opp_table *opp_table;
        struct device_node *opp_table_np;

        opp_table_np = of_get_parent(opp_np);
        if (!opp_table_np)
                goto err;

        /* It is safe to put the node now as all we need now is its address */
        of_node_put(opp_table_np);

        mutex_lock(&opp_table_lock);
        list_for_each_entry(opp_table, &opp_tables, node) {
                if (opp_table_np == opp_table->np) {
                        _get_opp_table_kref(opp_table);
                        mutex_unlock(&opp_table_lock);
                        return opp_table;
                }
        }
        mutex_unlock(&opp_table_lock);

err:
        return ERR_PTR(-ENODEV);
}

/* Free resources previously acquired by _opp_table_alloc_required_tables() */
static void _opp_table_free_required_tables(struct opp_table *opp_table)
{
        struct opp_table **required_opp_tables = opp_table->required_opp_tables;
        int i;

        if (!required_opp_tables)
                return;

        for (i = 0; i < opp_table->required_opp_count; i++) {
                if (IS_ERR_OR_NULL(required_opp_tables[i]))
                        continue;

                dev_pm_opp_put_opp_table(required_opp_tables[i]);
        }

        kfree(required_opp_tables);

        opp_table->required_opp_count = 0;
        opp_table->required_opp_tables = NULL;

        mutex_lock(&opp_table_lock);
        list_del(&opp_table->lazy);
        mutex_unlock(&opp_table_lock);
}

/*
 * Populate all devices and opp tables which are part of "required-opps" list.
 * Checking only the first OPP node should be enough.
 */
static void _opp_table_alloc_required_tables(struct opp_table *opp_table,
                                             struct device *dev,
                                             struct device_node *opp_np)
{
        struct opp_table **required_opp_tables;
        struct device_node *required_np, *np;
        bool lazy = false;
        int count, i, size;

        /* Traversing the first OPP node is all we need */
        np = of_get_next_available_child(opp_np, NULL);
        if (!np) {
                dev_warn(dev, "Empty OPP table\n");

                return;
        }

        count = of_count_phandle_with_args(np, "required-opps", NULL);
        if (count <= 0)
                goto put_np;

        size = sizeof(*required_opp_tables) + sizeof(*opp_table->required_devs);
        required_opp_tables = kcalloc(count, size, GFP_KERNEL);
        if (!required_opp_tables)
                goto put_np;

        opp_table->required_opp_tables = required_opp_tables;
        opp_table->required_devs = (void *)(required_opp_tables + count);
        opp_table->required_opp_count = count;

        for (i = 0; i < count; i++) {
                required_np = of_parse_required_opp(np, i);
                if (!required_np)
                        goto free_required_tables;

                required_opp_tables[i] = _find_table_of_opp_np(required_np);
                of_node_put(required_np);

                if (IS_ERR(required_opp_tables[i]))
                        lazy = true;
        }

        /* Let's do the linking later on */
        if (lazy) {
                /*
                 * The OPP table is not held while allocating the table, take it
                 * now to avoid corruption to the lazy_opp_tables list.
                 */
                mutex_lock(&opp_table_lock);
                list_add(&opp_table->lazy, &lazy_opp_tables);
                mutex_unlock(&opp_table_lock);
        }

        goto put_np;

free_required_tables:
        _opp_table_free_required_tables(opp_table);
put_np:
        of_node_put(np);
}

void _of_init_opp_table(struct opp_table *opp_table, struct device *dev,
                        int index)
{
        struct device_node *np, *opp_np;
        u32 val;

        /*
         * Only required for backward compatibility with v1 bindings, but isn't
         * harmful for other cases. And so we do it unconditionally.
         */
        np = of_node_get(dev->of_node);
        if (!np)
                return;

        if (!of_property_read_u32(np, "clock-latency", &val))
                opp_table->clock_latency_ns_max = val;
        of_property_read_u32(np, "voltage-tolerance",
                             &opp_table->voltage_tolerance_v1);

        if (of_property_present(np, "#power-domain-cells"))
                opp_table->is_genpd = true;

        /* Get OPP table node */
        opp_np = _opp_of_get_opp_desc_node(np, index);
        of_node_put(np);

        if (!opp_np)
                return;

        if (of_property_read_bool(opp_np, "opp-shared"))
                opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
        else
                opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;

        opp_table->np = opp_np;

        _opp_table_alloc_required_tables(opp_table, dev, opp_np);
}

void _of_clear_opp_table(struct opp_table *opp_table)
{
        _opp_table_free_required_tables(opp_table);
        of_node_put(opp_table->np);
}

/*
 * Release all resources previously acquired with a call to
 * _of_opp_alloc_required_opps().
 */
static void _of_opp_free_required_opps(struct opp_table *opp_table,
                                       struct dev_pm_opp *opp)
{
        struct dev_pm_opp **required_opps = opp->required_opps;
        int i;

        if (!required_opps)
                return;

        for (i = 0; i < opp_table->required_opp_count; i++) {
                if (!required_opps[i])
                        continue;

                /* Put the reference back */
                dev_pm_opp_put(required_opps[i]);
        }

        opp->required_opps = NULL;
        kfree(required_opps);
}

void _of_clear_opp(struct opp_table *opp_table, struct dev_pm_opp *opp)
{
        _of_opp_free_required_opps(opp_table, opp);
        of_node_put(opp->np);
}

static int _link_required_opps(struct dev_pm_opp *opp, struct opp_table *opp_table,
                               struct opp_table *required_table, int index)
{
        struct device_node *np;

        np = of_parse_required_opp(opp->np, index);
        if (unlikely(!np))
                return -ENODEV;

        opp->required_opps[index] = _find_opp_of_np(required_table, np);
        of_node_put(np);

        if (!opp->required_opps[index]) {
                pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
                       __func__, opp->np, index);
                return -ENODEV;
        }

        /*
         * There are two genpd (as required-opp) cases that we need to handle,
         * devices with a single genpd and ones with multiple genpds.
         *
         * The single genpd case requires special handling as we need to use the
         * same `dev` structure (instead of a virtual one provided by genpd
         * core) for setting the performance state.
         *
         * It doesn't make sense for a device's DT entry to have both
         * "opp-level" and single "required-opps" entry pointing to a genpd's
         * OPP, as that would make the OPP core call
         * dev_pm_domain_set_performance_state() for two different values for
         * the same device structure. Lets treat single genpd configuration as a
         * case where the OPP's level is directly available without required-opp
         * link in the DT.
         *
         * Just update the `level` with the right value, which
         * dev_pm_opp_set_opp() will take care of in the normal path itself.
         *
         * There is another case though, where a genpd's OPP table has
         * required-opps set to a parent genpd. The OPP core expects the user to
         * set the respective required `struct device` pointer via
         * dev_pm_opp_set_config().
         */
        if (required_table->is_genpd && opp_table->required_opp_count == 1 &&
            !opp_table->required_devs[0]) {
                /* Genpd core takes care of propagation to parent genpd */
                if (!opp_table->is_genpd) {
                        if (!WARN_ON(opp->level != OPP_LEVEL_UNSET))
                                opp->level = opp->required_opps[0]->level;
                }
        }

        return 0;
}

/* Populate all required OPPs which are part of "required-opps" list */
static int _of_opp_alloc_required_opps(struct opp_table *opp_table,
                                       struct dev_pm_opp *opp)
{
        struct opp_table *required_table;
        int i, ret, count = opp_table->required_opp_count;

        if (!count)
                return 0;

        opp->required_opps = kcalloc(count, sizeof(*opp->required_opps), GFP_KERNEL);
        if (!opp->required_opps)
                return -ENOMEM;

        for (i = 0; i < count; i++) {
                required_table = opp_table->required_opp_tables[i];

                /* Required table not added yet, we will link later */
                if (IS_ERR_OR_NULL(required_table))
                        continue;

                ret = _link_required_opps(opp, opp_table, required_table, i);
                if (ret)
                        goto free_required_opps;
        }

        return 0;

free_required_opps:
        _of_opp_free_required_opps(opp_table, opp);

        return ret;
}

/* Link required OPPs for an individual OPP */
static int lazy_link_required_opps(struct opp_table *opp_table,
                                   struct opp_table *new_table, int index)
{
        struct dev_pm_opp *opp;
        int ret;

        list_for_each_entry(opp, &opp_table->opp_list, node) {
                ret = _link_required_opps(opp, opp_table, new_table, index);
                if (ret)
                        return ret;
        }

        return 0;
}

/* Link required OPPs for all OPPs of the newly added OPP table */
static void lazy_link_required_opp_table(struct opp_table *new_table)
{
        struct opp_table *opp_table, *temp, **required_opp_tables;
        struct device_node *required_np, *opp_np, *required_table_np;
        struct dev_pm_opp *opp;
        int i, ret;

        mutex_lock(&opp_table_lock);

        list_for_each_entry_safe(opp_table, temp, &lazy_opp_tables, lazy) {
                bool lazy = false;

                /* opp_np can't be invalid here */
                opp_np = of_get_next_available_child(opp_table->np, NULL);

                for (i = 0; i < opp_table->required_opp_count; i++) {
                        required_opp_tables = opp_table->required_opp_tables;

                        /* Required opp-table is already parsed */
                        if (!IS_ERR(required_opp_tables[i]))
                                continue;

                        /* required_np can't be invalid here */
                        required_np = of_parse_required_opp(opp_np, i);
                        required_table_np = of_get_parent(required_np);

                        of_node_put(required_table_np);
                        of_node_put(required_np);

                        /*
                         * Newly added table isn't the required opp-table for
                         * opp_table.
                         */
                        if (required_table_np != new_table->np) {
                                lazy = true;
                                continue;
                        }

                        required_opp_tables[i] = new_table;
                        _get_opp_table_kref(new_table);

                        /* Link OPPs now */
                        ret = lazy_link_required_opps(opp_table, new_table, i);
                        if (ret) {
                                /* The OPPs will be marked unusable */
                                lazy = false;
                                break;
                        }
                }

                of_node_put(opp_np);

                /* All required opp-tables found, remove from lazy list */
                if (!lazy) {
                        list_del_init(&opp_table->lazy);

                        list_for_each_entry(opp, &opp_table->opp_list, node)
                                _required_opps_available(opp, opp_table->required_opp_count);
                }
        }

        mutex_unlock(&opp_table_lock);
}

static int _bandwidth_supported(struct device *dev, struct opp_table *opp_table)
{
        struct device_node *np, *opp_np;
        struct property *prop;

        if (!opp_table) {
                np = of_node_get(dev->of_node);
                if (!np)
                        return -ENODEV;

                opp_np = _opp_of_get_opp_desc_node(np, 0);
                of_node_put(np);
        } else {
                opp_np = of_node_get(opp_table->np);
        }

        /* Lets not fail in case we are parsing opp-v1 bindings */
        if (!opp_np)
                return 0;

        /* Checking only first OPP is sufficient */
        np = of_get_next_available_child(opp_np, NULL);
        of_node_put(opp_np);
        if (!np) {
                dev_err(dev, "OPP table empty\n");
                return -EINVAL;
        }

        prop = of_find_property(np, "opp-peak-kBps", NULL);
        of_node_put(np);

        if (!prop || !prop->length)
                return 0;

        return 1;
}

int dev_pm_opp_of_find_icc_paths(struct device *dev,
                                 struct opp_table *opp_table)
{
        struct device_node *np;
        int ret, i, count, num_paths;
        struct icc_path **paths;

        ret = _bandwidth_supported(dev, opp_table);
        if (ret == -EINVAL)
                return 0; /* Empty OPP table is a valid corner-case, let's not fail */
        else if (ret <= 0)
                return ret;

        ret = 0;

        np = of_node_get(dev->of_node);
        if (!np)
                return 0;

        count = of_count_phandle_with_args(np, "interconnects",
                                           "#interconnect-cells");
        of_node_put(np);
        if (count < 0)
                return 0;

        /* two phandles when #interconnect-cells = <1> */
        if (count % 2) {
                dev_err(dev, "%s: Invalid interconnects values\n", __func__);
                return -EINVAL;
        }

        num_paths = count / 2;
        paths = kcalloc(num_paths, sizeof(*paths), GFP_KERNEL);
        if (!paths)
                return -ENOMEM;

        for (i = 0; i < num_paths; i++) {
                paths[i] = of_icc_get_by_index(dev, i);
                if (IS_ERR(paths[i])) {
                        ret = dev_err_probe(dev, PTR_ERR(paths[i]), "%s: Unable to get path%d\n", __func__, i);
                        goto err;
                }
        }

        if (opp_table) {
                opp_table->paths = paths;
                opp_table->path_count = num_paths;
                return 0;
        }

err:
        while (i--)
                icc_put(paths[i]);

        kfree(paths);

        return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_find_icc_paths);

static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
                              struct device_node *np)
{
        unsigned int levels = opp_table->supported_hw_count;
        int count, versions, ret, i, j;
        u32 val;

        if (!opp_table->supported_hw) {
                /*
                 * In the case that no supported_hw has been set by the
                 * platform but there is an opp-supported-hw value set for
                 * an OPP then the OPP should not be enabled as there is
                 * no way to see if the hardware supports it.
                 */
                if (of_property_present(np, "opp-supported-hw"))
                        return false;
                else
                        return true;
        }

        count = of_property_count_u32_elems(np, "opp-supported-hw");
        if (count <= 0 || count % levels) {
                dev_err(dev, "%s: Invalid opp-supported-hw property (%d)\n",
                        __func__, count);
                return false;
        }

        versions = count / levels;

        /* All levels in at least one of the versions should match */
        for (i = 0; i < versions; i++) {
                bool supported = true;

                for (j = 0; j < levels; j++) {
                        ret = of_property_read_u32_index(np, "opp-supported-hw",
                                                         i * levels + j, &val);
                        if (ret) {
                                dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
                                         __func__, i * levels + j, ret);
                                return false;
                        }

                        /* Check if the level is supported */
                        if (!(val & opp_table->supported_hw[j])) {
                                supported = false;
                                break;
                        }
                }

                if (supported)
                        return true;
        }

        return false;
}

static u32 *_parse_named_prop(struct dev_pm_opp *opp, struct device *dev,
                              struct opp_table *opp_table,
                              const char *prop_type, bool *triplet)
{
        struct property *prop = NULL;
        char name[NAME_MAX];
        int count, ret;
        u32 *out;

        /* Search for "opp-<prop_type>-<name>" */
        if (opp_table->prop_name) {
                snprintf(name, sizeof(name), "opp-%s-%s", prop_type,
                         opp_table->prop_name);
                prop = of_find_property(opp->np, name, NULL);
        }

        if (!prop) {
                /* Search for "opp-<prop_type>" */
                snprintf(name, sizeof(name), "opp-%s", prop_type);
                prop = of_find_property(opp->np, name, NULL);
                if (!prop)
                        return NULL;
        }

        count = of_property_count_u32_elems(opp->np, name);
        if (count < 0) {
                dev_err(dev, "%s: Invalid %s property (%d)\n", __func__, name,
                        count);
                return ERR_PTR(count);
        }

        /*
         * Initialize regulator_count, if regulator information isn't provided
         * by the platform. Now that one of the properties is available, fix the
         * regulator_count to 1.
         */
        if (unlikely(opp_table->regulator_count == -1))
                opp_table->regulator_count = 1;

        if (count != opp_table->regulator_count &&
            (!triplet || count != opp_table->regulator_count * 3)) {
                dev_err(dev, "%s: Invalid number of elements in %s property (%u) with supplies (%d)\n",
                        __func__, prop_type, count, opp_table->regulator_count);
                return ERR_PTR(-EINVAL);
        }

        out = kmalloc_array(count, sizeof(*out), GFP_KERNEL);
        if (!out)
                return ERR_PTR(-EINVAL);

        ret = of_property_read_u32_array(opp->np, name, out, count);
        if (ret) {
                dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
                kfree(out);
                return ERR_PTR(-EINVAL);
        }

        if (triplet)
                *triplet = count != opp_table->regulator_count;

        return out;
}

static u32 *opp_parse_microvolt(struct dev_pm_opp *opp, struct device *dev,
                                struct opp_table *opp_table, bool *triplet)
{
        u32 *microvolt;

        microvolt = _parse_named_prop(opp, dev, opp_table, "microvolt", triplet);
        if (IS_ERR(microvolt))
                return microvolt;

        if (!microvolt) {
                /*
                 * Missing property isn't a problem, but an invalid
                 * entry is. This property isn't optional if regulator
                 * information is provided. Check only for the first OPP, as
                 * regulator_count may get initialized after that to a valid
                 * value.
                 */
                if (list_empty(&opp_table->opp_list) &&
                    opp_table->regulator_count > 0) {
                        dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
                                __func__);
                        return ERR_PTR(-EINVAL);
                }
        }

        return microvolt;
}

static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
                              struct opp_table *opp_table)
{
        u32 *microvolt, *microamp, *microwatt;
        int ret = 0, i, j;
        bool triplet;

        microvolt = opp_parse_microvolt(opp, dev, opp_table, &triplet);
        if (IS_ERR(microvolt))
                return PTR_ERR(microvolt);

        microamp = _parse_named_prop(opp, dev, opp_table, "microamp", NULL);
        if (IS_ERR(microamp)) {
                ret = PTR_ERR(microamp);
                goto free_microvolt;
        }

        microwatt = _parse_named_prop(opp, dev, opp_table, "microwatt", NULL);
        if (IS_ERR(microwatt)) {
                ret = PTR_ERR(microwatt);
                goto free_microamp;
        }

        /*
         * Initialize regulator_count if it is uninitialized and no properties
         * are found.
         */
        if (unlikely(opp_table->regulator_count == -1)) {
                opp_table->regulator_count = 0;
                return 0;
        }

        for (i = 0, j = 0; i < opp_table->regulator_count; i++) {
                if (microvolt) {
                        opp->supplies[i].u_volt = microvolt[j++];

                        if (triplet) {
                                opp->supplies[i].u_volt_min = microvolt[j++];
                                opp->supplies[i].u_volt_max = microvolt[j++];
                        } else {
                                opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
                                opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
                        }
                }

                if (microamp)
                        opp->supplies[i].u_amp = microamp[i];

                if (microwatt)
                        opp->supplies[i].u_watt = microwatt[i];
        }

        kfree(microwatt);
free_microamp:
        kfree(microamp);
free_microvolt:
        kfree(microvolt);

        return ret;
}

/**
 * dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT
 *                                entries
 * @dev:        device pointer used to lookup OPP table.
 *
 * Free OPPs created using static entries present in DT.
 */
void dev_pm_opp_of_remove_table(struct device *dev)
{
        dev_pm_opp_remove_table(dev);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);

static int _read_rate(struct dev_pm_opp *new_opp, struct opp_table *opp_table,
                      struct device_node *np)
{
        struct property *prop;
        int i, count, ret;
        u64 *rates;

        prop = of_find_property(np, "opp-hz", NULL);
        if (!prop)
                return -ENODEV;

        count = prop->length / sizeof(u64);
        if (opp_table->clk_count != count) {
                pr_err("%s: Count mismatch between opp-hz and clk_count (%d %d)\n",
                       __func__, count, opp_table->clk_count);
                return -EINVAL;
        }

        rates = kmalloc_array(count, sizeof(*rates), GFP_KERNEL);
        if (!rates)
                return -ENOMEM;

        ret = of_property_read_u64_array(np, "opp-hz", rates, count);
        if (ret) {
                pr_err("%s: Error parsing opp-hz: %d\n", __func__, ret);
        } else {
                /*
                 * Rate is defined as an unsigned long in clk API, and so
                 * casting explicitly to its type. Must be fixed once rate is 64
                 * bit guaranteed in clk API.
                 */
                for (i = 0; i < count; i++) {
                        new_opp->rates[i] = (unsigned long)rates[i];

                        /* This will happen for frequencies > 4.29 GHz */
                        WARN_ON(new_opp->rates[i] != rates[i]);
                }
        }

        kfree(rates);

        return ret;
}

static int _read_bw(struct dev_pm_opp *new_opp, struct opp_table *opp_table,
                    struct device_node *np, bool peak)
{
        const char *name = peak ? "opp-peak-kBps" : "opp-avg-kBps";
        struct property *prop;
        int i, count, ret;
        u32 *bw;

        prop = of_find_property(np, name, NULL);
        if (!prop)
                return -ENODEV;

        count = prop->length / sizeof(u32);
        if (opp_table->path_count != count) {
                pr_err("%s: Mismatch between %s and paths (%d %d)\n",
                                __func__, name, count, opp_table->path_count);
                return -EINVAL;
        }

        bw = kmalloc_array(count, sizeof(*bw), GFP_KERNEL);
        if (!bw)
                return -ENOMEM;

        ret = of_property_read_u32_array(np, name, bw, count);
        if (ret) {
                pr_err("%s: Error parsing %s: %d\n", __func__, name, ret);
                goto out;
        }

        for (i = 0; i < count; i++) {
                if (peak)
                        new_opp->bandwidth[i].peak = kBps_to_icc(bw[i]);
                else
                        new_opp->bandwidth[i].avg = kBps_to_icc(bw[i]);
        }

out:
        kfree(bw);
        return ret;
}

static int _read_opp_key(struct dev_pm_opp *new_opp,
                         struct opp_table *opp_table, struct device_node *np)
{
        bool found = false;
        int ret;

        ret = _read_rate(new_opp, opp_table, np);
        if (!ret)
                found = true;
        else if (ret != -ENODEV)
                return ret;

        /*
         * Bandwidth consists of peak and average (optional) values:
         * opp-peak-kBps = <path1_value path2_value>;
         * opp-avg-kBps = <path1_value path2_value>;
         */
        ret = _read_bw(new_opp, opp_table, np, true);
        if (!ret) {
                found = true;
                ret = _read_bw(new_opp, opp_table, np, false);
        }

        /* The properties were found but we failed to parse them */
        if (ret && ret != -ENODEV)
                return ret;

        if (!of_property_read_u32(np, "opp-level", &new_opp->level))
                found = true;

        if (found)
                return 0;

        return ret;
}

/**
 * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
 * @opp_table:  OPP table
 * @dev:        device for which we do this operation
 * @np:         device node
 *
 * This function adds an opp definition to the opp table and returns status. The
 * opp can be controlled using dev_pm_opp_enable/disable functions and may be
 * removed by dev_pm_opp_remove.
 *
 * Return:
 * Valid OPP pointer:
 *              On success
 * NULL:
 *              Duplicate OPPs (both freq and volt are same) and opp->available
 *              OR if the OPP is not supported by hardware.
 * ERR_PTR(-EEXIST):
 *              Freq are same and volt are different OR
 *              Duplicate OPPs (both freq and volt are same) and !opp->available
 * ERR_PTR(-ENOMEM):
 *              Memory allocation failure
 * ERR_PTR(-EINVAL):
 *              Failed parsing the OPP node
 */
static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
                struct device *dev, struct device_node *np)
{
        struct dev_pm_opp *new_opp;
        u32 val;
        int ret;

        new_opp = _opp_allocate(opp_table);
        if (!new_opp)
                return ERR_PTR(-ENOMEM);

        ret = _read_opp_key(new_opp, opp_table, np);
        if (ret < 0) {
                dev_err(dev, "%s: opp key field not found\n", __func__);
                goto free_opp;
        }

        /* Check if the OPP supports hardware's hierarchy of versions or not */
        if (!_opp_is_supported(dev, opp_table, np)) {
                dev_dbg(dev, "OPP not supported by hardware: %s\n",
                        of_node_full_name(np));
                goto free_opp;
        }

        new_opp->turbo = of_property_read_bool(np, "turbo-mode");

        new_opp->np = of_node_get(np);
        new_opp->dynamic = false;
        new_opp->available = true;

        ret = _of_opp_alloc_required_opps(opp_table, new_opp);
        if (ret)
                goto free_opp;

        if (!of_property_read_u32(np, "clock-latency-ns", &val))
                new_opp->clock_latency_ns = val;

        ret = opp_parse_supplies(new_opp, dev, opp_table);
        if (ret)
                goto free_required_opps;

        ret = _opp_add(dev, new_opp, opp_table);
        if (ret) {
                /* Don't return error for duplicate OPPs */
                if (ret == -EBUSY)
                        ret = 0;
                goto free_required_opps;
        }

        /* OPP to select on device suspend */
        if (of_property_read_bool(np, "opp-suspend")) {
                if (opp_table->suspend_opp) {
                        /* Pick the OPP with higher rate/bw/level as suspend OPP */
                        if (_opp_compare_key(opp_table, new_opp, opp_table->suspend_opp) == 1) {
                                opp_table->suspend_opp->suspend = false;
                                new_opp->suspend = true;
                                opp_table->suspend_opp = new_opp;
                        }
                } else {
                        new_opp->suspend = true;
                        opp_table->suspend_opp = new_opp;
                }
        }

        if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
                opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;

        pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu level:%u\n",
                 __func__, new_opp->turbo, new_opp->rates[0],
                 new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min,
                 new_opp->supplies[0].u_volt_max, new_opp->clock_latency_ns,
                 new_opp->level);

        /*
         * Notify the changes in the availability of the operable
         * frequency/voltage list.
         */
        blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
        return new_opp;

free_required_opps:
        _of_opp_free_required_opps(opp_table, new_opp);
free_opp:
        _opp_free(new_opp);

        return ret ? ERR_PTR(ret) : NULL;
}

/* Initializes OPP tables based on new bindings */
static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
{
        struct device_node *np;
        int ret, count = 0;
        struct dev_pm_opp *opp;

        /* OPP table is already initialized for the device */
        mutex_lock(&opp_table->lock);
        if (opp_table->parsed_static_opps) {
                opp_table->parsed_static_opps++;
                mutex_unlock(&opp_table->lock);
                return 0;
        }

        opp_table->parsed_static_opps = 1;
        mutex_unlock(&opp_table->lock);

        /* We have opp-table node now, iterate over it and add OPPs */
        for_each_available_child_of_node(opp_table->np, np) {
                opp = _opp_add_static_v2(opp_table, dev, np);
                if (IS_ERR(opp)) {
                        ret = PTR_ERR(opp);
                        dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
                                ret);
                        of_node_put(np);
                        goto remove_static_opp;
                } else if (opp) {
                        count++;
                }
        }

        /* There should be one or more OPPs defined */
        if (!count) {
                dev_err(dev, "%s: no supported OPPs", __func__);
                ret = -ENOENT;
                goto remove_static_opp;
        }

        lazy_link_required_opp_table(opp_table);

        return 0;

remove_static_opp:
        _opp_remove_all_static(opp_table);

        return ret;
}

/* Initializes OPP tables based on old-deprecated bindings */
static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
{
        const struct property *prop;
        const __be32 *val;
        int nr, ret = 0;

        mutex_lock(&opp_table->lock);
        if (opp_table->parsed_static_opps) {
                opp_table->parsed_static_opps++;
                mutex_unlock(&opp_table->lock);
                return 0;
        }

        opp_table->parsed_static_opps = 1;
        mutex_unlock(&opp_table->lock);

        prop = of_find_property(dev->of_node, "operating-points", NULL);
        if (!prop) {
                ret = -ENODEV;
                goto remove_static_opp;
        }
        if (!prop->value) {
                ret = -ENODATA;
                goto remove_static_opp;
        }

        /*
         * Each OPP is a set of tuples consisting of frequency and
         * voltage like <freq-kHz vol-uV>.
         */
        nr = prop->length / sizeof(u32);
        if (nr % 2) {
                dev_err(dev, "%s: Invalid OPP table\n", __func__);
                ret = -EINVAL;
                goto remove_static_opp;
        }

        val = prop->value;
        while (nr) {
                unsigned long freq = be32_to_cpup(val++) * 1000;
                unsigned long volt = be32_to_cpup(val++);
                struct dev_pm_opp_data data = {
                        .freq = freq,
                        .u_volt = volt,
                };

                ret = _opp_add_v1(opp_table, dev, &data, false);
                if (ret) {
                        dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
                                __func__, data.freq, ret);
                        goto remove_static_opp;
                }
                nr -= 2;
        }

        return 0;

remove_static_opp:
        _opp_remove_all_static(opp_table);

        return ret;
}

static int _of_add_table_indexed(struct device *dev, int index)
{
        struct opp_table *opp_table;
        int ret, count;

        if (index) {
                /*
                 * If only one phandle is present, then the same OPP table
                 * applies for all index requests.
                 */
                count = of_count_phandle_with_args(dev->of_node,
                                                   "operating-points-v2", NULL);
                if (count == 1)
                        index = 0;
        }

        opp_table = _add_opp_table_indexed(dev, index, true);
        if (IS_ERR(opp_table))
                return PTR_ERR(opp_table);

        /*
         * OPPs have two version of bindings now. Also try the old (v1)
         * bindings for backward compatibility with older dtbs.
         */
        if (opp_table->np)
                ret = _of_add_opp_table_v2(dev, opp_table);
        else
                ret = _of_add_opp_table_v1(dev, opp_table);

        if (ret)
                dev_pm_opp_put_opp_table(opp_table);

        return ret;
}

static void devm_pm_opp_of_table_release(void *data)
{
        dev_pm_opp_of_remove_table(data);
}

static int _devm_of_add_table_indexed(struct device *dev, int index)
{
        int ret;

        ret = _of_add_table_indexed(dev, index);
        if (ret)
                return ret;

        return devm_add_action_or_reset(dev, devm_pm_opp_of_table_release, dev);
}

/**
 * devm_pm_opp_of_add_table() - Initialize opp table from device tree
 * @dev:        device pointer used to lookup OPP table.
 *
 * Register the initial OPP table with the OPP library for given device.
 *
 * The opp_table structure will be freed after the device is destroyed.
 *
 * Return:
 * 0            On success OR
 *              Duplicate OPPs (both freq and volt are same) and opp->available
 * -EEXIST      Freq are same and volt are different OR
 *              Duplicate OPPs (both freq and volt are same) and !opp->available
 * -ENOMEM      Memory allocation failure
 * -ENODEV      when 'operating-points' property is not found or is invalid data
 *              in device node.
 * -ENODATA     when empty 'operating-points' property is found
 * -EINVAL      when invalid entries are found in opp-v2 table
 */
int devm_pm_opp_of_add_table(struct device *dev)
{
        return _devm_of_add_table_indexed(dev, 0);
}
EXPORT_SYMBOL_GPL(devm_pm_opp_of_add_table);

/**
 * dev_pm_opp_of_add_table() - Initialize opp table from device tree
 * @dev:        device pointer used to lookup OPP table.
 *
 * Register the initial OPP table with the OPP library for given device.
 *
 * Return:
 * 0            On success OR
 *              Duplicate OPPs (both freq and volt are same) and opp->available
 * -EEXIST      Freq are same and volt are different OR
 *              Duplicate OPPs (both freq and volt are same) and !opp->available
 * -ENOMEM      Memory allocation failure
 * -ENODEV      when 'operating-points' property is not found or is invalid data
 *              in device node.
 * -ENODATA     when empty 'operating-points' property is found
 * -EINVAL      when invalid entries are found in opp-v2 table
 */
int dev_pm_opp_of_add_table(struct device *dev)
{
        return _of_add_table_indexed(dev, 0);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);

/**
 * dev_pm_opp_of_add_table_indexed() - Initialize indexed opp table from device tree
 * @dev:        device pointer used to lookup OPP table.
 * @index:      Index number.
 *
 * Register the initial OPP table with the OPP library for given device only
 * using the "operating-points-v2" property.
 *
 * Return: Refer to dev_pm_opp_of_add_table() for return values.
 */
int dev_pm_opp_of_add_table_indexed(struct device *dev, int index)
{
        return _of_add_table_indexed(dev, index);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table_indexed);

/**
 * devm_pm_opp_of_add_table_indexed() - Initialize indexed opp table from device tree
 * @dev:        device pointer used to lookup OPP table.
 * @index:      Index number.
 *
 * This is a resource-managed variant of dev_pm_opp_of_add_table_indexed().
 */
int devm_pm_opp_of_add_table_indexed(struct device *dev, int index)
{
        return _devm_of_add_table_indexed(dev, index);
}
EXPORT_SYMBOL_GPL(devm_pm_opp_of_add_table_indexed);

/* CPU device specific helpers */

/**
 * dev_pm_opp_of_cpumask_remove_table() - Removes OPP table for @cpumask
 * @cpumask:    cpumask for which OPP table needs to be removed
 *
 * This removes the OPP tables for CPUs present in the @cpumask.
 * This should be used only to remove static entries created from DT.
 */
void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask)
{
        _dev_pm_opp_cpumask_remove_table(cpumask, -1);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);

/**
 * dev_pm_opp_of_cpumask_add_table() - Adds OPP table for @cpumask
 * @cpumask:    cpumask for which OPP table needs to be added.
 *
 * This adds the OPP tables for CPUs present in the @cpumask.
 */
int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask)
{
        struct device *cpu_dev;
        int cpu, ret;

        if (WARN_ON(cpumask_empty(cpumask)))
                return -ENODEV;

        for_each_cpu(cpu, cpumask) {
                cpu_dev = get_cpu_device(cpu);
                if (!cpu_dev) {
                        pr_err("%s: failed to get cpu%d device\n", __func__,
                               cpu);
                        ret = -ENODEV;
                        goto remove_table;
                }

                ret = dev_pm_opp_of_add_table(cpu_dev);
                if (ret) {
                        /*
                         * OPP may get registered dynamically, don't print error
                         * message here.
                         */
                        pr_debug("%s: couldn't find opp table for cpu:%d, %d\n",
                                 __func__, cpu, ret);

                        goto remove_table;
                }
        }

        return 0;

remove_table:
        /* Free all other OPPs */
        _dev_pm_opp_cpumask_remove_table(cpumask, cpu);

        return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);

/*
 * Works only for OPP v2 bindings.
 *
 * Returns -ENOENT if operating-points-v2 bindings aren't supported.
 */
/**
 * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with
 *                                    @cpu_dev using operating-points-v2
 *                                    bindings.
 *
 * @cpu_dev:    CPU device for which we do this operation
 * @cpumask:    cpumask to update with information of sharing CPUs
 *
 * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
 *
 * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
 */
int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
                                   struct cpumask *cpumask)
{
        struct device_node *np, *tmp_np, *cpu_np;
        int cpu, ret = 0;

        /* Get OPP descriptor node */
        np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
        if (!np) {
                dev_dbg(cpu_dev, "%s: Couldn't find opp node.\n", __func__);
                return -ENOENT;
        }

        cpumask_set_cpu(cpu_dev->id, cpumask);

        /* OPPs are shared ? */
        if (!of_property_read_bool(np, "opp-shared"))
                goto put_cpu_node;

        for_each_possible_cpu(cpu) {
                if (cpu == cpu_dev->id)
                        continue;

                cpu_np = of_cpu_device_node_get(cpu);
                if (!cpu_np) {
                        dev_err(cpu_dev, "%s: failed to get cpu%d node\n",
                                __func__, cpu);
                        ret = -ENOENT;
                        goto put_cpu_node;
                }

                /* Get OPP descriptor node */
                tmp_np = _opp_of_get_opp_desc_node(cpu_np, 0);
                of_node_put(cpu_np);
                if (!tmp_np) {
                        pr_err("%pOF: Couldn't find opp node\n", cpu_np);
                        ret = -ENOENT;
                        goto put_cpu_node;
                }

                /* CPUs are sharing opp node */
                if (np == tmp_np)
                        cpumask_set_cpu(cpu, cpumask);

                of_node_put(tmp_np);
        }

put_cpu_node:
        of_node_put(np);
        return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);

/**
 * of_get_required_opp_performance_state() - Search for required OPP and return its performance state.
 * @np: Node that contains the "required-opps" property.
 * @index: Index of the phandle to parse.
 *
 * Returns the performance state of the OPP pointed out by the "required-opps"
 * property at @index in @np.
 *
 * Return: Zero or positive performance state on success, otherwise negative
 * value on errors.
 */
int of_get_required_opp_performance_state(struct device_node *np, int index)
{
        struct dev_pm_opp *opp;
        struct device_node *required_np;
        struct opp_table *opp_table;
        int pstate = -EINVAL;

        required_np = of_parse_required_opp(np, index);
        if (!required_np)
                return -ENODEV;

        opp_table = _find_table_of_opp_np(required_np);
        if (IS_ERR(opp_table)) {
                pr_err("%s: Failed to find required OPP table %pOF: %ld\n",
                       __func__, np, PTR_ERR(opp_table));
                goto put_required_np;
        }

        /* The OPP tables must belong to a genpd */
        if (unlikely(!opp_table->is_genpd)) {
                pr_err("%s: Performance state is only valid for genpds.\n", __func__);
                goto put_required_np;
        }

        opp = _find_opp_of_np(opp_table, required_np);
        if (opp) {
                if (opp->level == OPP_LEVEL_UNSET) {
                        pr_err("%s: OPP levels aren't available for %pOF\n",
                               __func__, np);
                } else {
                        pstate = opp->level;
                }
                dev_pm_opp_put(opp);

        }

        dev_pm_opp_put_opp_table(opp_table);

put_required_np:
        of_node_put(required_np);

        return pstate;
}
EXPORT_SYMBOL_GPL(of_get_required_opp_performance_state);

/**
 * dev_pm_opp_of_has_required_opp - Find out if a required-opps exists.
 * @dev: The device to investigate.
 *
 * Returns true if the device's node has a "operating-points-v2" property and if
 * the corresponding node for the opp-table describes opp nodes that uses the
 * "required-opps" property.
 *
 * Return: True if a required-opps is present, else false.
 */
bool dev_pm_opp_of_has_required_opp(struct device *dev)
{
        struct device_node *opp_np, *np;
        int count;

        opp_np = _opp_of_get_opp_desc_node(dev->of_node, 0);
        if (!opp_np)
                return false;

        np = of_get_next_available_child(opp_np, NULL);
        of_node_put(opp_np);
        if (!np) {
                dev_warn(dev, "Empty OPP table\n");
                return false;
        }

        count = of_count_phandle_with_args(np, "required-opps", NULL);
        of_node_put(np);

        return count > 0;
}

/**
 * dev_pm_opp_get_of_node() - Gets the DT node corresponding to an opp
 * @opp:        opp for which DT node has to be returned for
 *
 * Return: DT node corresponding to the opp, else 0 on success.
 *
 * The caller needs to put the node with of_node_put() after using it.
 */
struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
{
        if (IS_ERR_OR_NULL(opp)) {
                pr_err("%s: Invalid parameters\n", __func__);
                return NULL;
        }

        return of_node_get(opp->np);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);

/*
 * Callback function provided to the Energy Model framework upon registration.
 * It provides the power used by @dev at @kHz if it is the frequency of an
 * existing OPP, or at the frequency of the first OPP above @kHz otherwise
 * (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
 * frequency and @uW to the associated power.
 *
 * Returns 0 on success or a proper -EINVAL value in case of error.
 */
static int __maybe_unused
_get_dt_power(struct device *dev, unsigned long *uW, unsigned long *kHz)
{
        struct dev_pm_opp *opp;
        unsigned long opp_freq, opp_power;

        /* Find the right frequency and related OPP */
        opp_freq = *kHz * 1000;
        opp = dev_pm_opp_find_freq_ceil(dev, &opp_freq);
        if (IS_ERR(opp))
                return -EINVAL;

        opp_power = dev_pm_opp_get_power(opp);
        dev_pm_opp_put(opp);
        if (!opp_power)
                return -EINVAL;

        *kHz = opp_freq / 1000;
        *uW = opp_power;

        return 0;
}

/**
 * dev_pm_opp_calc_power() - Calculate power value for device with EM
 * @dev         : Device for which an Energy Model has to be registered
 * @uW          : New power value that is calculated
 * @kHz         : Frequency for which the new power is calculated
 *
 * This computes the power estimated by @dev at @kHz if it is the frequency
 * of an existing OPP, or at the frequency of the first OPP above @kHz otherwise
 * (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
 * frequency and @uW to the associated power. The power is estimated as
 * P = C * V^2 * f with C being the device's capacitance and V and f
 * respectively the voltage and frequency of the OPP.
 * It is also used as a callback function provided to the Energy Model
 * framework upon registration.
 *
 * Returns -EINVAL if the power calculation failed because of missing
 * parameters, 0 otherwise.
 */
int dev_pm_opp_calc_power(struct device *dev, unsigned long *uW,
                          unsigned long *kHz)
{
        struct dev_pm_opp *opp;
        struct device_node *np;
        unsigned long mV, Hz;
        u32 cap;
        u64 tmp;
        int ret;

        np = of_node_get(dev->of_node);
        if (!np)
                return -EINVAL;

        ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
        of_node_put(np);
        if (ret)
                return -EINVAL;

        Hz = *kHz * 1000;
        opp = dev_pm_opp_find_freq_ceil(dev, &Hz);
        if (IS_ERR(opp))
                return -EINVAL;

        mV = dev_pm_opp_get_voltage(opp) / 1000;
        dev_pm_opp_put(opp);
        if (!mV)
                return -EINVAL;

        tmp = (u64)cap * mV * mV * (Hz / 1000000);
        /* Provide power in micro-Watts */
        do_div(tmp, 1000000);

        *uW = (unsigned long)tmp;
        *kHz = Hz / 1000;

        return 0;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_calc_power);

static bool _of_has_opp_microwatt_property(struct device *dev)
{
        unsigned long power, freq = 0;
        struct dev_pm_opp *opp;

        /* Check if at least one OPP has needed property */
        opp = dev_pm_opp_find_freq_ceil(dev, &freq);
        if (IS_ERR(opp))
                return false;

        power = dev_pm_opp_get_power(opp);
        dev_pm_opp_put(opp);
        if (!power)
                return false;

        return true;
}

/**
 * dev_pm_opp_of_register_em() - Attempt to register an Energy Model
 * @dev         : Device for which an Energy Model has to be registered
 * @cpus        : CPUs for which an Energy Model has to be registered. For
 *              other type of devices it should be set to NULL.
 *
 * This checks whether the "dynamic-power-coefficient" devicetree property has
 * been specified, and tries to register an Energy Model with it if it has.
 * Having this property means the voltages are known for OPPs and the EM
 * might be calculated.
 */
int dev_pm_opp_of_register_em(struct device *dev, struct cpumask *cpus)
{
        struct em_data_callback em_cb;
        struct device_node *np;
        int ret, nr_opp;
        u32 cap;

        if (IS_ERR_OR_NULL(dev)) {
                ret = -EINVAL;
                goto failed;
        }

        nr_opp = dev_pm_opp_get_opp_count(dev);
        if (nr_opp <= 0) {
                ret = -EINVAL;
                goto failed;
        }

        /* First, try to find more precised Energy Model in DT */
        if (_of_has_opp_microwatt_property(dev)) {
                EM_SET_ACTIVE_POWER_CB(em_cb, _get_dt_power);
                goto register_em;
        }

        np = of_node_get(dev->of_node);
        if (!np) {
                ret = -EINVAL;
                goto failed;
        }

        /*
         * Register an EM only if the 'dynamic-power-coefficient' property is
         * set in devicetree. It is assumed the voltage values are known if that
         * property is set since it is useless otherwise. If voltages are not
         * known, just let the EM registration fail with an error to alert the
         * user about the inconsistent configuration.
         */
        ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
        of_node_put(np);
        if (ret || !cap) {
                dev_dbg(dev, "Couldn't find proper 'dynamic-power-coefficient' in DT\n");
                ret = -EINVAL;
                goto failed;
        }

        EM_SET_ACTIVE_POWER_CB(em_cb, dev_pm_opp_calc_power);

register_em:
        ret = em_dev_register_perf_domain(dev, nr_opp, &em_cb, cpus, true);
        if (ret)
                goto failed;

        return 0;

failed:
        dev_dbg(dev, "Couldn't register Energy Model %d\n", ret);
        return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_register_em);