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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/opp/of.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/opp/of.c')
-rw-r--r--drivers/opp/of.c1621
1 files changed, 1621 insertions, 0 deletions
diff --git a/drivers/opp/of.c b/drivers/opp/of.c
new file mode 100644
index 000000000..605d68673
--- /dev/null
+++ b/drivers/opp/of.c
@@ -0,0 +1,1621 @@
+// 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_device.h>
+#include <linux/pm_domain.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/energy_model.h>
+
+#include "opp.h"
+
+/*
+ * 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;
+ list_del(&opp_table->lazy);
+}
+
+/*
+ * 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;
+
+ /* 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;
+
+ required_opp_tables = kcalloc(count, sizeof(*required_opp_tables),
+ GFP_KERNEL);
+ if (!required_opp_tables)
+ goto put_np;
+
+ opp_table->required_opp_tables = required_opp_tables;
+ 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)
+ list_add(&opp_table->lazy, &lazy_opp_tables);
+
+ 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_find_property(np, "#power-domain-cells", NULL))
+ 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);
+}
+
+/* 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 dev_pm_opp **required_opps;
+ struct opp_table *required_table;
+ struct device_node *np;
+ int i, ret, count = opp_table->required_opp_count;
+
+ if (!count)
+ return 0;
+
+ required_opps = kcalloc(count, sizeof(*required_opps), GFP_KERNEL);
+ if (!required_opps)
+ return -ENOMEM;
+
+ opp->required_opps = required_opps;
+
+ 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;
+
+ np = of_parse_required_opp(opp->np, i);
+ if (unlikely(!np)) {
+ ret = -ENODEV;
+ goto free_required_opps;
+ }
+
+ required_opps[i] = _find_opp_of_np(required_table, np);
+ of_node_put(np);
+
+ if (!required_opps[i]) {
+ pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
+ __func__, opp->np, i);
+ ret = -ENODEV;
+ 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 device_node *required_np;
+ struct dev_pm_opp *opp;
+
+ list_for_each_entry(opp, &opp_table->opp_list, node) {
+ required_np = of_parse_required_opp(opp->np, index);
+ if (unlikely(!required_np))
+ return -ENODEV;
+
+ opp->required_opps[index] = _find_opp_of_np(new_table, required_np);
+ of_node_put(required_np);
+
+ if (!opp->required_opps[index]) {
+ pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
+ __func__, opp->np, index);
+ return -ENODEV;
+ }
+ }
+
+ 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 = PTR_ERR(paths[i]);
+ if (ret != -EPROBE_DEFER) {
+ dev_err(dev, "%s: Unable to get path%d: %d\n",
+ __func__, i, ret);
+ }
+ 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_find_property(np, "opp-supported-hw", NULL))
+ 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 int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
+ struct opp_table *opp_table)
+{
+ u32 *microvolt, *microamp = NULL, *microwatt = NULL;
+ int supplies = opp_table->regulator_count;
+ int vcount, icount, pcount, ret, i, j;
+ struct property *prop = NULL;
+ char name[NAME_MAX];
+
+ /* Search for "opp-microvolt-<name>" */
+ if (opp_table->prop_name) {
+ snprintf(name, sizeof(name), "opp-microvolt-%s",
+ opp_table->prop_name);
+ prop = of_find_property(opp->np, name, NULL);
+ }
+
+ if (!prop) {
+ /* Search for "opp-microvolt" */
+ sprintf(name, "opp-microvolt");
+ prop = of_find_property(opp->np, name, NULL);
+
+ /* Missing property isn't a problem, but an invalid entry is */
+ if (!prop) {
+ if (unlikely(supplies == -1)) {
+ /* Initialize regulator_count */
+ opp_table->regulator_count = 0;
+ return 0;
+ }
+
+ if (!supplies)
+ return 0;
+
+ dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
+ __func__);
+ return -EINVAL;
+ }
+ }
+
+ if (unlikely(supplies == -1)) {
+ /* Initialize regulator_count */
+ supplies = opp_table->regulator_count = 1;
+ } else if (unlikely(!supplies)) {
+ dev_err(dev, "%s: opp-microvolt wasn't expected\n", __func__);
+ return -EINVAL;
+ }
+
+ vcount = of_property_count_u32_elems(opp->np, name);
+ if (vcount < 0) {
+ dev_err(dev, "%s: Invalid %s property (%d)\n",
+ __func__, name, vcount);
+ return vcount;
+ }
+
+ /* There can be one or three elements per supply */
+ if (vcount != supplies && vcount != supplies * 3) {
+ dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
+ __func__, name, vcount, supplies);
+ return -EINVAL;
+ }
+
+ microvolt = kmalloc_array(vcount, sizeof(*microvolt), GFP_KERNEL);
+ if (!microvolt)
+ return -ENOMEM;
+
+ ret = of_property_read_u32_array(opp->np, name, microvolt, vcount);
+ if (ret) {
+ dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
+ ret = -EINVAL;
+ goto free_microvolt;
+ }
+
+ /* Search for "opp-microamp-<name>" */
+ prop = NULL;
+ if (opp_table->prop_name) {
+ snprintf(name, sizeof(name), "opp-microamp-%s",
+ opp_table->prop_name);
+ prop = of_find_property(opp->np, name, NULL);
+ }
+
+ if (!prop) {
+ /* Search for "opp-microamp" */
+ sprintf(name, "opp-microamp");
+ prop = of_find_property(opp->np, name, NULL);
+ }
+
+ if (prop) {
+ icount = of_property_count_u32_elems(opp->np, name);
+ if (icount < 0) {
+ dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
+ name, icount);
+ ret = icount;
+ goto free_microvolt;
+ }
+
+ if (icount != supplies) {
+ dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
+ __func__, name, icount, supplies);
+ ret = -EINVAL;
+ goto free_microvolt;
+ }
+
+ microamp = kmalloc_array(icount, sizeof(*microamp), GFP_KERNEL);
+ if (!microamp) {
+ ret = -EINVAL;
+ goto free_microvolt;
+ }
+
+ ret = of_property_read_u32_array(opp->np, name, microamp,
+ icount);
+ if (ret) {
+ dev_err(dev, "%s: error parsing %s: %d\n", __func__,
+ name, ret);
+ ret = -EINVAL;
+ goto free_microamp;
+ }
+ }
+
+ /* Search for "opp-microwatt" */
+ sprintf(name, "opp-microwatt");
+ prop = of_find_property(opp->np, name, NULL);
+
+ if (prop) {
+ pcount = of_property_count_u32_elems(opp->np, name);
+ if (pcount < 0) {
+ dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
+ name, pcount);
+ ret = pcount;
+ goto free_microamp;
+ }
+
+ if (pcount != supplies) {
+ dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
+ __func__, name, pcount, supplies);
+ ret = -EINVAL;
+ goto free_microamp;
+ }
+
+ microwatt = kmalloc_array(pcount, sizeof(*microwatt),
+ GFP_KERNEL);
+ if (!microwatt) {
+ ret = -EINVAL;
+ goto free_microamp;
+ }
+
+ ret = of_property_read_u32_array(opp->np, name, microwatt,
+ pcount);
+ if (ret) {
+ dev_err(dev, "%s: error parsing %s: %d\n", __func__,
+ name, ret);
+ ret = -EINVAL;
+ goto free_microwatt;
+ }
+ }
+
+ for (i = 0, j = 0; i < supplies; i++) {
+ opp->supplies[i].u_volt = microvolt[j++];
+
+ if (vcount == supplies) {
+ opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
+ opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
+ } else {
+ opp->supplies[i].u_volt_min = microvolt[j++];
+ opp->supplies[i].u_volt_max = microvolt[j++];
+ }
+
+ if (microamp)
+ opp->supplies[i].u_amp = microamp[i];
+
+ if (microwatt)
+ opp->supplies[i].u_watt = microwatt[i];
+ }
+
+free_microwatt:
+ 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;
+
+ if (opp_table->is_genpd)
+ new_opp->pstate = pm_genpd_opp_to_performance_state(dev, new_opp);
+
+ 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;
+ }
+
+ list_for_each_entry(opp, &opp_table->opp_list, node) {
+ /* Any non-zero performance state would enable the feature */
+ if (opp->pstate) {
+ opp_table->genpd_performance_state = true;
+ break;
+ }
+ }
+
+ 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++);
+
+ ret = _opp_add_v1(opp_table, dev, freq, volt, false);
+ if (ret) {
+ dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
+ __func__, 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;
+ }
+
+ opp = _find_opp_of_np(opp_table, required_np);
+ if (opp) {
+ pstate = opp->pstate;
+ 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_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;
+}
+
+/*
+ * Callback function provided to the Energy Model framework upon registration.
+ * 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.
+ *
+ * Returns -EINVAL if the power calculation failed because of missing
+ * parameters, 0 otherwise.
+ */
+static int __maybe_unused _get_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;
+}
+
+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, _get_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);