[PATCH v5 1/7] PM / devfreq: Set min/max_freq when adding the devfreq device

Chanwoo Choi
2017-10-23T01:35:15Z

Prior to that, the min/max_freq of the devfreq device are always zero
before the user changes the min/max_freq through sysfs entries.
It might make the confusion for the min/max_freq.

This patch initializes the available min/max_freq by using the OPP
during adding the devfreq device.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
---
drivers/devfreq/devfreq.c | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index a1c4ee818614..6a6f88bccdee 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -69,6 +69,34 @@ static struct devfreq *find_device_devfreq(struct device *dev)
return ERR_PTR(-ENODEV);
}

+static unsigned long find_available_min_freq(struct devfreq *devfreq)
+{
+ struct dev_pm_opp *opp;
+ unsigned long min_freq = 0;
+
+ opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &min_freq);
+ if (IS_ERR(opp))
+ min_freq = 0;
+ else
+ dev_pm_opp_put(opp);
+
+ return min_freq;
+}
+
+static unsigned long find_available_max_freq(struct devfreq *devfreq)
+{
+ struct dev_pm_opp *opp;
+ unsigned long max_freq = ULONG_MAX;
+
+ opp = dev_pm_opp_find_freq_floor(devfreq->dev.parent, &max_freq);
+ if (IS_ERR(opp))
+ max_freq = 0;
+ else
+ dev_pm_opp_put(opp);
+
+ return max_freq;
+}
+
/**
* devfreq_get_freq_level() - Lookup freq_table for the frequency
* @devfreq: the devfreq instance
@@ -559,6 +587,20 @@ struct devfreq *devfreq_add_device(struct device *dev,
mutex_lock(&devfreq->lock);
}

+ devfreq->min_freq = find_available_min_freq(devfreq);
+ if (!devfreq->min_freq) {
+ mutex_unlock(&devfreq->lock);
+ err = -EINVAL;
+ goto err_dev;
+ }
+
+ devfreq->max_freq = find_available_max_freq(devfreq);
+ if (!devfreq->max_freq) {
+ mutex_unlock(&devfreq->lock);
+ err = -EINVAL;
+ goto err_dev;
+ }
+
dev_set_name(&devfreq->dev, "devfreq%d",
atomic_inc_return(&devfreq_no));
err = device_register(&devfreq->dev);
--
1.9.1