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-rw-r--r--Documentation/devicetree/bindings/opp/opp.txt54
-rw-r--r--drivers/opp/of.c7
2 files changed, 58 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/opp/opp.txt b/Documentation/devicetree/bindings/opp/opp.txt
index 9847dfeeffcb..08b3da4736cf 100644
--- a/Documentation/devicetree/bindings/opp/opp.txt
+++ b/Documentation/devicetree/bindings/opp/opp.txt
@@ -65,7 +65,9 @@ Required properties:
- OPP nodes: One or more OPP nodes describing voltage-current-frequency
combinations. Their name isn't significant but their phandle can be used to
- reference an OPP.
+ reference an OPP. These are mandatory except for the case where the OPP table
+ is present only to indicate dependency between devices using the opp-shared
+ property.
Optional properties:
- opp-shared: Indicates that device nodes using this OPP Table Node's phandle
@@ -568,3 +570,53 @@ Example 6: opp-microvolt-<name>, opp-microamp-<name>:
};
};
};
+
+Example 7: Single cluster Quad-core ARM cortex A53, OPP points from firmware,
+distinct clock controls but two sets of clock/voltage/current lines.
+
+/ {
+ cpus {
+ #address-cells = <2>;
+ #size-cells = <0>;
+
+ cpu@0 {
+ compatible = "arm,cortex-a53";
+ reg = <0x0 0x100>;
+ next-level-cache = <&A53_L2>;
+ clocks = <&dvfs_controller 0>;
+ operating-points-v2 = <&cpu_opp0_table>;
+ };
+ cpu@1 {
+ compatible = "arm,cortex-a53";
+ reg = <0x0 0x101>;
+ next-level-cache = <&A53_L2>;
+ clocks = <&dvfs_controller 1>;
+ operating-points-v2 = <&cpu_opp0_table>;
+ };
+ cpu@2 {
+ compatible = "arm,cortex-a53";
+ reg = <0x0 0x102>;
+ next-level-cache = <&A53_L2>;
+ clocks = <&dvfs_controller 2>;
+ operating-points-v2 = <&cpu_opp1_table>;
+ };
+ cpu@3 {
+ compatible = "arm,cortex-a53";
+ reg = <0x0 0x103>;
+ next-level-cache = <&A53_L2>;
+ clocks = <&dvfs_controller 3>;
+ operating-points-v2 = <&cpu_opp1_table>;
+ };
+
+ };
+
+ cpu_opp0_table: opp0_table {
+ compatible = "operating-points-v2";
+ opp-shared;
+ };
+
+ cpu_opp1_table: opp1_table {
+ compatible = "operating-points-v2";
+ opp-shared;
+ };
+};
diff --git a/drivers/opp/of.c b/drivers/opp/of.c
index 6b7f0066942d..d41088578aab 100644
--- a/drivers/opp/of.c
+++ b/drivers/opp/of.c
@@ -170,7 +170,8 @@ static void _opp_table_alloc_required_tables(struct opp_table *opp_table,
/* 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");
+ dev_warn(dev, "Empty OPP table\n");
+
return;
}
@@ -378,7 +379,9 @@ int dev_pm_opp_of_find_icc_paths(struct device *dev,
struct icc_path **paths;
ret = _bandwidth_supported(dev, opp_table);
- if (ret <= 0)
+ if (ret == -EINVAL)
+ return 0; /* Empty OPP table is a valid corner-case, let's not fail */
+ else if (ret <= 0)
return ret;
ret = 0;