thermal: cpu_cooling: introduce of_cpufreq_cooling_register

This patch introduces an API to register cpufreq cooling device
based on device tree node.

The registration via device tree node differs from normal
registration due to the fact that it is needed to fill
the device_node structure in order to be able to match
the cooling devices with trip points.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
(cherry picked from commit 39d99cff76bf2992fd6dd4b1fc62da139e62e90c)

Signed-off-by: Alex Shi <alex.shi@linaro.org>

Conflicts:
	drivers/thermal/Kconfig
	drivers/thermal/cpu_cooling.c

2 files changed, 52 insertions, 7 deletions

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 3630c074f461..e92e1dcb6e3f 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -91,6 +91,7 @@ config THERMAL_GOV_USER_SPACE
 config CPU_THERMAL
 	bool "generic cpu cooling support"
 	depends on CPU_FREQ
+	depends on THERMAL_OF
 	select CPU_FREQ_TABLE
 	help
 	  This implements the generic cpu cooling mechanism through frequency
diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
index c94bf2e5de62..78de7947afac 100644
--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -415,18 +415,21 @@ static struct notifier_block thermal_cpufreq_notifier_block = {
 };
 
 /**
- * cpufreq_cooling_register - function to create cpufreq cooling device.
+ * __cpufreq_cooling_register - helper function to create cpufreq cooling device
+ * @np: a valid struct device_node to the cooling device device tree node
  * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
  *
  * This interface function registers the cpufreq cooling device with the name
  * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
- * cooling devices.
+ * cooling devices. It also gives the opportunity to link the cooling device
+ * with a device tree node, in order to bind it via the thermal DT code.
  *
  * Return: a valid struct thermal_cooling_device pointer on success,
  * on failure, it returns a corresponding ERR_PTR().
  */
-struct thermal_cooling_device *
-cpufreq_cooling_register(const struct cpumask *clip_cpus)
+static struct thermal_cooling_device *
+__cpufreq_cooling_register(struct device_node *np,
+			   const struct cpumask *clip_cpus)
 {
 	struct thermal_cooling_device *cool_dev;
 	struct cpufreq_cooling_device *cpufreq_dev = NULL;
@@ -465,9 +468,9 @@ cpufreq_cooling_register(const struct cpumask *clip_cpus)
 	snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d",
 		 cpufreq_dev->id);
 
-	cool_dev = thermal_cooling_device_register(dev_name, cpufreq_dev,
-						   &cpufreq_cooling_ops);
-	if (!cool_dev) {
+	cool_dev = thermal_of_cooling_device_register(np, dev_name, cpufreq_dev,
+						      &cpufreq_cooling_ops);
+	if (IS_ERR(cool_dev)) {
 		release_idr(&cpufreq_idr, cpufreq_dev->id);
 		kfree(cpufreq_dev);
 		return ERR_PTR(-EINVAL);
@@ -486,9 +489,50 @@ cpufreq_cooling_register(const struct cpumask *clip_cpus)
 
 	return cool_dev;
 }
+
+/**
+ * cpufreq_cooling_register - function to create cpufreq cooling device.
+ * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
+ *
+ * This interface function registers the cpufreq cooling device with the name
+ * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
+ * cooling devices.
+ *
+ * Return: a valid struct thermal_cooling_device pointer on success,
+ * on failure, it returns a corresponding ERR_PTR().
+ */
+struct thermal_cooling_device *
+cpufreq_cooling_register(const struct cpumask *clip_cpus)
+{
+	return __cpufreq_cooling_register(NULL, clip_cpus);
+}
 EXPORT_SYMBOL_GPL(cpufreq_cooling_register);
 
 /**
+ * of_cpufreq_cooling_register - function to create cpufreq cooling device.
+ * @np: a valid struct device_node to the cooling device device tree node
+ * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
+ *
+ * This interface function registers the cpufreq cooling device with the name
+ * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
+ * cooling devices. Using this API, the cpufreq cooling device will be
+ * linked to the device tree node provided.
+ *
+ * Return: a valid struct thermal_cooling_device pointer on success,
+ * on failure, it returns a corresponding ERR_PTR().
+ */
+struct thermal_cooling_device *
+of_cpufreq_cooling_register(struct device_node *np,
+			    const struct cpumask *clip_cpus)
+{
+	if (!np)
+		return ERR_PTR(-EINVAL);
+
+	return __cpufreq_cooling_register(np, clip_cpus);
+}
+EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register);
+
+/**
  * cpufreq_cooling_unregister - function to remove cpufreq cooling device.
  * @cdev: thermal cooling device pointer.
  *