[PATCH V15 RESEND 2/5] thermal: of-thermal: add API for getting sensor ID from DT

Anson Huang
2020-02-20T01:17:00Z

This patch adds new API thermal_zone_of_get_sensor_id() to
provide the feature of getting sensor ID from DT thermal
zone's node. It's useful for thermal driver to register the
specific thermal zone devices from DT in a common way.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
---
Changes since V14:
- improve the commit message and comment, no code change.
---
drivers/thermal/of-thermal.c | 65 +++++++++++++++++++++++++++++++++-----------
include/linux/thermal.h | 10 +++++++
2 files changed, 59 insertions(+), 16 deletions(-)

diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
index ef0baa9..0f57108 100644
--- a/drivers/thermal/of-thermal.c
+++ b/drivers/thermal/of-thermal.c
@@ -449,6 +449,53 @@ thermal_zone_of_add_sensor(struct device_node *zone,
}

/**
+ * thermal_zone_of_get_sensor_id - get sensor ID from a DT thermal zone
+ * @tz_np: a valid thermal zone device node.
+ * @sensor_np: a sensor node of a valid sensor device.
+ * @id: the sensor ID returned if success.
+ *
+ * This function will get sensor ID from a given thermal zone node and
+ * the sensor node must match the temperature provider @sensor_np.
+ *
+ * Return: 0 on success, proper error code otherwise.
+ */
+
+int thermal_zone_of_get_sensor_id(struct device_node *tz_np,
+ struct device_node *sensor_np,
+ u32 *id)
+{
+ struct of_phandle_args sensor_specs;
+ int ret;
+
+ ret = of_parse_phandle_with_args(tz_np,
+ "thermal-sensors",
+ "#thermal-sensor-cells",
+ 0,
+ &sensor_specs);
+ if (ret)
+ return ret;
+
+ if (sensor_specs.np != sensor_np) {
+ of_node_put(sensor_specs.np);
+ return -ENODEV;
+ }
+
+ if (sensor_specs.args_count >= 1) {
+ *id = sensor_specs.args[0];
+ WARN(sensor_specs.args_count > 1,
+ "%pOFn: too many cells in sensor specifier %d\n",
+ sensor_specs.np, sensor_specs.args_count);
+ } else {
+ *id = 0;
+ }
+
+ of_node_put(sensor_specs.np);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(thermal_zone_of_get_sensor_id);
+
+/**
* thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
* @dev: a valid struct device pointer of a sensor device. Must contain
* a valid .of_node, for the sensor node.
@@ -499,36 +546,22 @@ thermal_zone_of_sensor_register(struct device *dev, int sensor_id, void *data,
sensor_np = of_node_get(dev->of_node);

for_each_available_child_of_node(np, child) {
- struct of_phandle_args sensor_specs;
int ret, id;

/* For now, thermal framework supports only 1 sensor per zone */
- ret = of_parse_phandle_with_args(child, "thermal-sensors",
- "#thermal-sensor-cells",
- 0, &sensor_specs);
+ ret = thermal_zone_of_get_sensor_id(child, sensor_np, &id);
if (ret)
continue;

- if (sensor_specs.args_count >= 1) {
- id = sensor_specs.args[0];
- WARN(sensor_specs.args_count > 1,
- "%pOFn: too many cells in sensor specifier %d\n",
- sensor_specs.np, sensor_specs.args_count);
- } else {
- id = 0;
- }
-
- if (sensor_specs.np == sensor_np && id == sensor_id) {
+ if (id == sensor_id) {
tzd = thermal_zone_of_add_sensor(child, sensor_np,
data, ops);
if (!IS_ERR(tzd))
tzd->ops->set_mode(tzd, THERMAL_DEVICE_ENABLED);

- of_node_put(sensor_specs.np);
of_node_put(child);
goto exit;
}
- of_node_put(sensor_specs.np);
}
exit:
of_node_put(sensor_np);
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 126913c6..53e6f67 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -364,6 +364,9 @@ struct thermal_trip {

/* Function declarations */
#ifdef CONFIG_THERMAL_OF
+int thermal_zone_of_get_sensor_id(struct device_node *tz_np,
+ struct device_node *sensor_np,
+ u32 *id);
struct thermal_zone_device *
thermal_zone_of_sensor_register(struct device *dev, int id, void *data,
const struct thermal_zone_of_device_ops *ops);
@@ -375,6 +378,13 @@ struct thermal_zone_device *devm_thermal_zone_of_sensor_register(
void devm_thermal_zone_of_sensor_unregister(struct device *dev,
struct thermal_zone_device *tz);
#else
+
+static int thermal_zone_of_get_sensor_id(struct device_node *tz_np,
+ struct device_node *sensor_np,
+ u32 *id)
+{
+ return -ENOENT;
+}
static inline struct thermal_zone_device *
thermal_zone_of_sensor_register(struct device *dev, int id, void *data,
const struct thermal_zone_of_device_ops *ops)
--
2.7.4