[PATCH v6 1/3] OPP: Add function to look up required OPP's for a given OPP

From: Hsin-Yi Wang
Date: Thu Feb 04 2021 - 03:15:51 EST


From: Saravana Kannan <saravanak@xxxxxxxxxx>

Add a function that allows looking up required OPPs given a source OPP
table, destination OPP table and the source OPP.

Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx>
Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
---
drivers/opp/core.c | 59 ++++++++++++++++++++++++++++++++++++++++++
include/linux/pm_opp.h | 7 +++++
2 files changed, 66 insertions(+)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index dc95d29e94c1b..fba67ae40aefc 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -2398,6 +2398,65 @@ devm_pm_opp_attach_genpd(struct device *dev, const char **names,
}
EXPORT_SYMBOL_GPL(devm_pm_opp_attach_genpd);

+/**
+ * dev_pm_opp_xlate_required_opp() - Find required OPP for @src_table OPP.
+ * @src_table: OPP table which has @dst_table as one of its required OPP table.
+ * @dst_table: Required OPP table of the @src_table.
+ *
+ * This function returns the OPP (present in @dst_table) pointed out by the
+ * "required-opps" property of the OPP (present in @src_table).
+ *
+ * The callers are required to call dev_pm_opp_put() for the returned OPP after
+ * use.
+ *
+ * Return: destination table OPP on success, otherwise -EINVAL or -ENODEV based
+ * on errors.
+ */
+struct dev_pm_opp *dev_pm_opp_xlate_required_opp(struct opp_table *src_table,
+ struct opp_table *dst_table,
+ struct dev_pm_opp *src_opp)
+{
+ struct dev_pm_opp *opp, *dest_opp = ERR_PTR(-EINVAL);
+ int i;
+
+ if (!src_table || !dst_table || !src_opp ||
+ !src_table->required_opp_tables)
+ return ERR_PTR(-EINVAL);
+
+ /* required-opps not fully initialized yet */
+ if (lazy_linking_pending(src_table))
+ return ERR_PTR(-EINVAL);
+
+ for (i = 0; i < src_table->required_opp_count; i++) {
+ if (src_table->required_opp_tables[i] == dst_table)
+ break;
+ }
+
+ if (unlikely(i == src_table->required_opp_count)) {
+ pr_err("%s: Couldn't find matching OPP table (%p: %p)\n",
+ __func__, src_table, dst_table);
+ return ERR_PTR(-ENODEV);
+ }
+
+ mutex_lock(&src_table->lock);
+
+ list_for_each_entry(opp, &src_table->opp_list, node) {
+ if (opp == src_opp) {
+ dest_opp = opp->required_opps[i];
+ dev_pm_opp_get(dest_opp);
+ goto unlock;
+ }
+ }
+
+ pr_err("%s: Couldn't find matching OPP (%p: %p)\n", __func__, src_table,
+ dst_table);
+
+unlock:
+ mutex_unlock(&src_table->lock);
+
+ return dest_opp;
+}
+
/**
* dev_pm_opp_xlate_performance_state() - Find required OPP's pstate for src_table.
* @src_table: OPP table which has dst_table as one of its required OPP table.
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index ab1d15ce559db..c0371efa4a0f2 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -156,6 +156,7 @@ struct opp_table *devm_pm_opp_register_set_opp_helper(struct device *dev, int (*
struct opp_table *dev_pm_opp_attach_genpd(struct device *dev, const char **names, struct device ***virt_devs);
void dev_pm_opp_detach_genpd(struct opp_table *opp_table);
struct opp_table *devm_pm_opp_attach_genpd(struct device *dev, const char **names, struct device ***virt_devs);
+struct dev_pm_opp *dev_pm_opp_xlate_required_opp(struct opp_table *src_table, struct opp_table *dst_table, struct dev_pm_opp *src_opp);
int dev_pm_opp_xlate_performance_state(struct opp_table *src_table, struct opp_table *dst_table, unsigned int pstate);
int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq);
int dev_pm_opp_set_opp(struct device *dev, struct dev_pm_opp *opp);
@@ -367,6 +368,12 @@ static inline struct opp_table *devm_pm_opp_attach_genpd(struct device *dev,
return ERR_PTR(-EOPNOTSUPP);
}

+static inline struct dev_pm_opp *dev_pm_opp_xlate_required_opp(struct opp_table *src_table,
+ struct opp_table *dst_table, struct dev_pm_opp *src_opp)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+
static inline int dev_pm_opp_xlate_performance_state(struct opp_table *src_table, struct opp_table *dst_table, unsigned int pstate)
{
return -EOPNOTSUPP;
--
2.30.0.365.g02bc693789-goog