[PATCH v3 6/6] interconnect: Add OPP table support for interconnects

Saravana Kannan
2019-07-03T01:10:46Z

Interconnect paths can have different performance points. Now that OPP
framework supports bandwidth OPP tables, add OPP table support for
interconnects.

Devices can use the interconnect-opp-table DT property to specify OPP
tables for interconnect paths. And the driver can obtain the OPP table for
an interconnect path by calling icc_get_opp_table().

Signed-off-by: Saravana Kannan <saravanak@google.com>
---
drivers/interconnect/core.c | 27 ++++++++++++++++++++++++++-
include/linux/interconnect.h | 7 +++++++
2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 871eb4bc4efc..881bac80bc1e 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -47,6 +47,7 @@ struct icc_req {
*/
struct icc_path {
size_t num_nodes;
+ struct opp_table *opp_table;
struct icc_req reqs[];
};

@@ -313,7 +314,7 @@ struct icc_path *of_icc_get(struct device *dev, const char *name)
{
struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
struct icc_node *src_node, *dst_node;
- struct device_node *np = NULL;
+ struct device_node *np = NULL, *opp_node;
struct of_phandle_args src_args, dst_args;
int idx = 0;
int ret;
@@ -381,10 +382,34 @@ struct icc_path *of_icc_get(struct device *dev, const char *name)
dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
mutex_unlock(&icc_lock);

+ opp_node = of_parse_phandle(np, "interconnect-opp-table", idx);
+ if (opp_node) {
+ path->opp_table = dev_pm_opp_of_find_table_from_node(opp_node);
+ of_node_put(opp_node);
+ }
+
+
return path;
}
EXPORT_SYMBOL_GPL(of_icc_get);

+/**
+ * icc_get_opp_table() - Get the OPP table that corresponds to a path
+ * @path: reference to the path returned by icc_get()
+ *
+ * This function will return the OPP table that corresponds to a path handle.
+ * If the interconnect API is disabled, NULL is returned and the consumer
+ * drivers will still build. Drivers are free to handle this specifically, but
+ * they don't have to.
+ *
+ * Return: opp_table pointer on success. NULL is returned when the API is
+ * disabled or the OPP table is missing.
+ */
+struct opp_table *icc_get_opp_table(struct icc_path *path)
+{
+ return path->opp_table;
+}
+
/**
* icc_set_bw() - set bandwidth constraints on an interconnect path
* @path: reference to the path returned by icc_get()
diff --git a/include/linux/interconnect.h b/include/linux/interconnect.h
index dc25864755ba..0c0bc55f0e89 100644
--- a/include/linux/interconnect.h
+++ b/include/linux/interconnect.h
@@ -9,6 +9,7 @@

#include <linux/mutex.h>
#include <linux/types.h>
+#include <linux/pm_opp.h>

/* macros for converting to icc units */
#define Bps_to_icc(x) ((x) / 1000)
@@ -28,6 +29,7 @@ struct device;
struct icc_path *icc_get(struct device *dev, const int src_id,
const int dst_id);
struct icc_path *of_icc_get(struct device *dev, const char *name);
+struct opp_table *icc_get_opp_table(struct icc_path *path);
void icc_put(struct icc_path *path);
int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw);

@@ -49,6 +51,11 @@ static inline void icc_put(struct icc_path *path)
{
}

+static inline struct opp_table *icc_get_opp_table(struct icc_path *path)
+{
+ return NULL;
+}
+
static inline int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw)
{
return 0;
--
2.22.0.410.gd8fdbe21b5-goog