thermal: of: improve of-thermal sensor registration API

Different drivers request API extensions in of-thermal. For this reason,
additional callbacks are required to fit the new drivers needs.

The current API implementation expects the registering sensor driver
to provide a get_temp and get_trend callbacks as function parameters.
As the amount of callbacks is growing, this patch changes the existing
implementation to use a .ops field to hold all the of thermal callbacks
to sensor drivers.

This patch also changes the existing of-thermal users to fit the new
API design. No functional change is introduced in this patch.

Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: devicetree@vger.kernel.org
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <jdelvare@suse.de>
Cc: linux-kernel@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-tegra@vger.kernel.org
Cc: lm-sensors@lm-sensors.org
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Mikko Perttunen <mikko.perttunen@kapsi.fi>
Reviewed-by: Mikko Perttunen <mikko.perttunen@kapsi.fi>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index ef90838..5bc28a7 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -289,19 +289,31 @@
 	enum events event;
 };
 
+/**
+ * struct thermal_zone_of_device_ops - scallbacks for handling DT based zones
+ *
+ * Mandatory:
+ * @get_temp: a pointer to a function that reads the sensor temperature.
+ *
+ * Optional:
+ * @get_trend: a pointer to a function that reads the sensor temperature trend.
+ */
+struct thermal_zone_of_device_ops {
+	int (*get_temp)(void *, long *);
+	int (*get_trend)(void *, long *);
+};
+
 /* Function declarations */
 #ifdef CONFIG_THERMAL_OF
 struct thermal_zone_device *
-thermal_zone_of_sensor_register(struct device *dev, int id,
-				void *data, int (*get_temp)(void *, long *),
-				int (*get_trend)(void *, long *));
+thermal_zone_of_sensor_register(struct device *dev, int id, void *data,
+				const struct thermal_zone_of_device_ops *ops);
 void thermal_zone_of_sensor_unregister(struct device *dev,
 				       struct thermal_zone_device *tz);
 #else
 static inline struct thermal_zone_device *
-thermal_zone_of_sensor_register(struct device *dev, int id,
-				void *data, int (*get_temp)(void *, long *),
-				int (*get_trend)(void *, long *))
+thermal_zone_of_sensor_register(struct device *dev, int id, void *data,
+				const struct thermal_zone_of_device_ops *ops)
 {
 	return NULL;
 }