[PATCH v3 3/4] thermal: of: parse stacked thermal zones from device tree

Javi Merino
2015-11-25T15:10:47Z

Now that devicetree specifies how to create a hierarchy of thermal
zones, let of-thermal parse it.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
---
drivers/thermal/of-thermal.c | 100 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 100 insertions(+)

diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
index 42b7d4253b94..7bbc0c32ee59 100644
--- a/drivers/thermal/of-thermal.c
+++ b/drivers/thermal/of-thermal.c
@@ -166,6 +166,27 @@ of_thermal_get_trip_points(struct thermal_zone_device *tz)
EXPORT_SYMBOL_GPL(of_thermal_get_trip_points);

/**
+ * of_thermal_is_thermal_zone - check that a device node corresponds to a thermal zone
+ * @np: the device node
+ *
+ * Valid thermal zone device nodes must provide the
+ * polling-delay-passive and polling-delay properties. This function
+ * checks if @np is thermal-zone node.
+ *
+ * Return: true if @np is a valid device for a thermal zone.
+ */
+static bool of_thermal_is_thermal_zone(struct device_node *np)
+{
+ u32 out;
+
+ if ((of_property_read_u32(np, "polling-delay-passive", &out)) ||
+ (of_property_read_u32(np, "polling-delay", &out)))
+ return false;
+
+ return true;
+}
+
+/**
* of_thermal_set_emul_temp - function to set emulated temperature
*
* @tz: pointer to a thermal zone
@@ -858,6 +879,82 @@ static inline void of_thermal_free_zone(struct __thermal_zone *tz)
}

/**
+ * link_stacked_thermal_zones - link thermal zones that are a superset of thermal zones
+ * @np: device node for the root of the thermal zones
+ *
+ * A thermal zone can specify other thermal zones as its input using
+ * the thermal-sensors property of device tree. This function parses
+ * all the thermal zones in dt and adds the thermal zones in their
+ * thermal-sensors as sub-thermalzones.
+ */
+static void link_stacked_thermal_zones(struct device_node *np)
+{
+ struct device_node *child;
+
+ for_each_child_of_node(np, child) {
+ int i, num_sensors;
+ struct thermal_zone_device *tz;
+
+ num_sensors = of_count_phandle_with_args(child,
+ "thermal-sensors",
+ "#thermal-sensor-cells");
+ if (num_sensors <= 0)
+ continue;
+
+ tz = thermal_zone_get_zone_by_name(child->name);
+ if (IS_ERR_OR_NULL(tz)) {
+ /*
+ * If the tz is available we should have added
+ * it in of_parse_thermal_zones()
+ */
+ WARN(of_device_is_available(child),
+ "Couldn't find thermal zone for %s\n",
+ of_node_full_name(child));
+ continue;
+ }
+
+ for (i = 0; i < num_sensors; i++) {
+ struct of_phandle_args sensor_specs;
+ struct thermal_zone_device *subtz;
+ int ret;
+
+ ret = of_parse_phandle_with_args(child,
+ "thermal-sensors",
+ "#thermal-sensor-cells",
+ i, &sensor_specs);
+ if (ret) {
+ pr_warn("Failed to parse thermal-sensors of %s: %d\n",
+ of_node_full_name(child), ret);
+ of_node_put(sensor_specs.np);
+ continue;
+ }
+
+ if (!of_thermal_is_thermal_zone(sensor_specs.np)) {
+ of_node_put(sensor_specs.np);
+ continue;
+ }
+
+ subtz = thermal_zone_get_zone_by_name(
+ sensor_specs.np->name);
+ if (IS_ERR_OR_NULL(subtz)) {
+ pr_warn("Couldn't find thermal zone for %s, is it disabled?\n",
+ of_node_full_name(sensor_specs.np));
+ of_node_put(sensor_specs.np);
+ continue;
+ }
+
+ ret = thermal_zone_add_subtz(tz, subtz,
+ THERMAL_WEIGHT_DEFAULT);
+ if (ret)
+ pr_warn("Failed to add thermal zone %s to %s: %d\n",
+ subtz->type, tz->type, ret);
+
+ of_node_put(sensor_specs.np);
+ }
+ }
+}
+
+/**
* of_parse_thermal_zones - parse device tree thermal data
*
* Initialization function that can be called by machine initialization
@@ -936,6 +1033,9 @@ int __init of_parse_thermal_zones(void)
/* attempting to build remaining zones still */
}
}
+
+ link_stacked_thermal_zones(np);
+
of_node_put(np);

return 0;
--
1.9.1