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path: root/drivers/opp/of.c
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Diffstat (limited to 'drivers/opp/of.c')
-rw-r--r--drivers/opp/of.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/drivers/opp/of.c b/drivers/opp/of.c
index 5f114cd3d88c..b5605196122a 100644
--- a/drivers/opp/of.c
+++ b/drivers/opp/of.c
@@ -73,6 +73,147 @@ struct opp_table *_managed_opp(struct device *dev, int index)
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;
+
+ lockdep_assert_held(&opp_table_lock);
+
+ 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)
+{
+ struct device_node *required_np;
+
+ required_np = of_parse_phandle(np, "required-opps", index);
+ if (unlikely(!required_np)) {
+ pr_err("%s: Unable to parse required-opps: %pOF, index: %d\n",
+ __func__, np, index);
+ }
+
+ return required_np;
+}
+
+/* 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 dev_pm_opp *opp;
+
+ lockdep_assert_held(&opp_table_lock);
+
+ list_for_each_entry(opp_table, &opp_tables, node) {
+ opp = _find_opp_of_np(opp_table, opp_np);
+ if (opp) {
+ dev_pm_opp_put(opp);
+ _get_opp_table_kref(opp_table);
+ return opp_table;
+ }
+ }
+
+ 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]))
+ break;
+
+ 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;
+}
+
+/*
+ * 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;
+ int count, i;
+
+ /* Traversing the first OPP node is all we need */
+ np = of_get_next_available_child(opp_np, NULL);
+ if (!np) {
+ dev_err(dev, "Empty OPP table\n");
+ return;
+ }
+
+ count = of_count_phandle_with_args(np, "required-opps", NULL);
+ if (!count)
+ 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]))
+ goto free_required_tables;
+
+ /*
+ * We only support genpd's OPPs in the "required-opps" for now,
+ * as we don't know how much about other cases. Error out if the
+ * required OPP doesn't belong to a genpd.
+ */
+ if (!required_opp_tables[i]->is_genpd) {
+ dev_err(dev, "required-opp doesn't belong to genpd: %pOF\n",
+ required_np);
+ goto free_required_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)
{
@@ -109,9 +250,15 @@ void _of_init_opp_table(struct opp_table *opp_table, struct device *dev,
opp_table->np = opp_np;
+ _opp_table_alloc_required_tables(opp_table, dev, opp_np);
of_node_put(opp_np);
}
+void _of_clear_opp_table(struct opp_table *opp_table)
+{
+ _opp_table_free_required_tables(opp_table);
+}
+
static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
struct device_node *np)
{