[PATCH v2 1/4] PM / devfreq: Add function to set max/min frequency

[Javi Merino <javi.merino@arm.com>]

From: Ørjan Eide <orjan.eide@arm.com>

Factor out the logic to set minimum and maximum frequency for the device
so that it can be used by other parts of the kernel.

Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Ørjan Eide <orjan.eide@arm.com>
---
Changes since v1:
  - Rename devfreq_qos_set_[max|min] to devfreq_set_[max|min] as
    suggested by MyungJoo Ham

 drivers/devfreq/devfreq.c | 72 +++++++++++++++++++++++++++++++----------------
 include/linux/devfreq.h   | 13 +++++++++
 2 files changed, 61 insertions(+), 24 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index ca1b362d77e2..5b3f2f32f1e5 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -768,6 +768,48 @@ err_out:
 }
 EXPORT_SYMBOL(devfreq_remove_governor);
 
+int devfreq_set_max(struct devfreq *df, unsigned long value)
+{
+	unsigned long min;
+	int ret = 0;
+
+	mutex_lock(&df->lock);
+	min = df->min_freq;
+	if (value && min && value < min) {
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	df->max_freq = value;
+	update_devfreq(df);
+unlock:
+	mutex_unlock(&df->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(devfreq_set_max);
+
+int devfreq_set_min(struct devfreq *df, unsigned long value)
+{
+	unsigned long max;
+	int ret = 0;
+
+	mutex_lock(&df->lock);
+	max = df->max_freq;
+	if (value && max && value > max) {
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	df->min_freq = value;
+	update_devfreq(df);
+unlock:
+	mutex_unlock(&df->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(devfreq_set_min);
+
 static ssize_t governor_show(struct device *dev,
 			     struct device_attribute *attr, char *buf)
 {
@@ -899,24 +941,15 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
 	struct devfreq *df = to_devfreq(dev);
 	unsigned long value;
 	int ret;
-	unsigned long max;
 
 	ret = sscanf(buf, "%lu", &value);
 	if (ret != 1)
 		return -EINVAL;
 
-	mutex_lock(&df->lock);
-	max = df->max_freq;
-	if (value && max && value > max) {
-		ret = -EINVAL;
-		goto unlock;
-	}
+	ret = devfreq_set_min(df, value);
+	if (!ret)
+		ret = count;
 
-	df->min_freq = value;
-	update_devfreq(df);
-	ret = count;
-unlock:
-	mutex_unlock(&df->lock);
 	return ret;
 }
 
@@ -932,24 +965,15 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
 	struct devfreq *df = to_devfreq(dev);
 	unsigned long value;
 	int ret;
-	unsigned long min;
 
 	ret = sscanf(buf, "%lu", &value);
 	if (ret != 1)
 		return -EINVAL;
 
-	mutex_lock(&df->lock);
-	min = df->min_freq;
-	if (value && min && value < min) {
-		ret = -EINVAL;
-		goto unlock;
-	}
+	ret = devfreq_set_max(df, value);
+	if (!ret)
+		ret = count;
 
-	df->max_freq = value;
-	update_devfreq(df);
-	ret = count;
-unlock:
-	mutex_unlock(&df->lock);
 	return ret;
 }
 static DEVICE_ATTR_RW(min_freq);
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index ce447f0f1bad..dce82c695955 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -204,6 +204,9 @@ extern int devm_devfreq_register_opp_notifier(struct device *dev,
 extern void devm_devfreq_unregister_opp_notifier(struct device *dev,
 						struct devfreq *devfreq);
 
+int devfreq_set_min(struct devfreq *df, unsigned long value);
+int devfreq_set_max(struct devfreq *df, unsigned long value);
+
 #if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)
 /**
  * struct devfreq_simple_ondemand_data - void *data fed to struct devfreq
@@ -289,6 +292,16 @@ static inline void devm_devfreq_unregister_opp_notifier(struct device *dev,
 							struct devfreq *devfreq)
 {
 }
+
+static inline int devfreq_set_min(struct devfreq *df, unsigned long value)
+{
+	return -EINVAL;
+}
+
+static inline int devfreq_set_max(struct devfreq *df, unsigned long value)
+{
+	return -EINVAL;
+}
 #endif /* CONFIG_PM_DEVFREQ */
 
 #endif /* __LINUX_DEVFREQ_H__ */
-- 
1.9.1