diff options
Diffstat (limited to 'drivers/opp/of.c')
| -rw-r--r-- | drivers/opp/of.c | 147 |
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) { |