2 files changed, 80 insertions, 0 deletions

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 0ce8069d6843..92fa94a6dcc1 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -1036,6 +1036,9 @@ int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
 		return ret;
 	}
 
+	if (opp_table->get_pstate)
+		new_opp->pstate = opp_table->get_pstate(dev, new_opp->rate);
+
 	list_add(&new_opp->node, head);
 	mutex_unlock(&opp_table->lock);
 
@@ -1548,6 +1551,81 @@ void dev_pm_opp_unregister_set_opp_helper(struct opp_table *opp_table)
 EXPORT_SYMBOL_GPL(dev_pm_opp_unregister_set_opp_helper);
 
 /**
+ * dev_pm_opp_register_get_pstate_helper() - Register get_pstate() helper.
+ * @dev: Device for which the helper is getting registered.
+ * @get_pstate: Helper.
+ *
+ * TODO: Remove this callback after the same information is available via Device
+ * Tree.
+ *
+ * This allows a platform to initialize the performance states of individual
+ * OPPs for its devices, until we get similar information directly from DT.
+ *
+ * This must be called before the OPPs are initialized for the device.
+ */
+struct opp_table *dev_pm_opp_register_get_pstate_helper(struct device *dev,
+		int (*get_pstate)(struct device *dev, unsigned long rate))
+{
+	struct opp_table *opp_table;
+	int ret;
+
+	if (!get_pstate)
+		return ERR_PTR(-EINVAL);
+
+	opp_table = dev_pm_opp_get_opp_table(dev);
+	if (!opp_table)
+		return ERR_PTR(-ENOMEM);
+
+	/* This should be called before OPPs are initialized */
+	if (WARN_ON(!list_empty(&opp_table->opp_list))) {
+		ret = -EBUSY;
+		goto err;
+	}
+
+	/* Already have genpd_performance_state set */
+	if (WARN_ON(opp_table->genpd_performance_state)) {
+		ret = -EBUSY;
+		goto err;
+	}
+
+	opp_table->genpd_performance_state = true;
+	opp_table->get_pstate = get_pstate;
+
+	return opp_table;
+
+err:
+	dev_pm_opp_put_opp_table(opp_table);
+
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_register_get_pstate_helper);
+
+/**
+ * dev_pm_opp_unregister_get_pstate_helper() - Releases resources blocked for
+ *					   get_pstate() helper
+ * @opp_table: OPP table returned from dev_pm_opp_register_get_pstate_helper().
+ *
+ * Release resources blocked for platform specific get_pstate() helper.
+ */
+void dev_pm_opp_unregister_get_pstate_helper(struct opp_table *opp_table)
+{
+	if (!opp_table->genpd_performance_state) {
+		pr_err("%s: Doesn't have performance states set\n",
+		       __func__);
+		return;
+	}
+
+	/* Make sure there are no concurrent readers while updating opp_table */
+	WARN_ON(!list_empty(&opp_table->opp_list));
+
+	opp_table->genpd_performance_state = false;
+	opp_table->get_pstate = NULL;
+
+	dev_pm_opp_put_opp_table(opp_table);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_unregister_get_pstate_helper);
+
+/**
  * dev_pm_opp_add()  - Add an OPP table from a table definitions
  * @dev:	device for which we do this operation
  * @freq:	Frequency in Hz for this OPP
diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h
index e8f767ab5814..4d00061648a3 100644
--- a/drivers/opp/opp.h
+++ b/drivers/opp/opp.h
@@ -140,6 +140,7 @@ enum opp_table_access {
  * @genpd_performance_state: Device's power domain support performance state.
  * @set_opp: Platform specific set_opp callback
  * @set_opp_data: Data to be passed to set_opp callback
+ * @get_pstate: Platform specific get_pstate callback
  * @dentry:	debugfs dentry pointer of the real device directory (not links).
  * @dentry_name: Name of the real dentry.
  *
@@ -177,6 +178,7 @@ struct opp_table {
 
 	int (*set_opp)(struct dev_pm_set_opp_data *data);
 	struct dev_pm_set_opp_data *set_opp_data;
+	int (*get_pstate)(struct device *dev, unsigned long rate);
 
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *dentry;